coll/base: silence misc warning

as reported by Coverity with CIDs 1363349-1363362

Offset temporary buffer when a non zero lower bound datatype is used.

Thanks Hristo Iliev for the report

(cherry picked from commit 0e393195d9f2373ffa9d59a240092f643117cd39)

ompi/mca/coll/basic/coll_basic_allgather.c

@@ -106,7 +106,7 @@ mca_coll_basic_allgather_inter(const void *sbuf, int scount,
         if (OMPI_SUCCESS != err) { line = __LINE__; goto exit; }
 
         /* Step 2: exchange the resuts between the root processes */
-        span = opal_datatype_span(&sdtype->super, scount * size, &gap);
+        span = opal_datatype_span(&sdtype->super, (int64_t)scount * (int64_t)size, &gap);
         tmpbuf_free = (char *) malloc(span);
         if (NULL == tmpbuf_free) { line = __LINE__; err = OMPI_ERR_OUT_OF_RESOURCE; goto exit; }
         tmpbuf = tmpbuf_free - gap;

ompi/mca/coll/basic/coll_basic_reduce_scatter_block.c

@@ -127,7 +127,7 @@ mca_coll_basic_reduce_scatter_block_inter(const void *sbuf, void *rbuf, int rcou
     int totalcounts;
     ptrdiff_t gap, span;
     char *tmpbuf = NULL, *tmpbuf2 = NULL;
-    char *lbuf, *buf;
+    char *lbuf = NULL, *buf;
     ompi_request_t *req;
 
     rank = ompi_comm_rank(comm);

ompi/mca/coll/inter/coll_inter_allgather.c

@@ -48,8 +48,8 @@ mca_coll_inter_allgather_inter(const void *sbuf, int scount,
                                struct ompi_communicator_t *comm,
                                mca_coll_base_module_t *module)
 {
-    int rank, root = 0, size, rsize, err;
-    char *ptmp_free = NULL, *ptmp;
+    int rank, root = 0, size, rsize, err = OMPI_SUCCESS;
+    char *ptmp_free = NULL, *ptmp = NULL;
     ptrdiff_t gap, span;
     ompi_request_t *req[2];
 
@@ -59,7 +59,7 @@ mca_coll_inter_allgather_inter(const void *sbuf, int scount,
 
     /* Perform the gather locally at the root */
     if ( scount > 0 ) {
-        span = opal_datatype_span(&sdtype->super, scount*size, &gap);
+        span = opal_datatype_span(&sdtype->super, (int64_t)scount*(int64_t)size, &gap);
 	ptmp_free = (char*)malloc(span);
 	if (NULL == ptmp_free) {
 	    return OMPI_ERR_OUT_OF_RESOURCE;

ompi/mca/coll/inter/coll_inter_allgatherv.c

@@ -49,7 +49,7 @@ mca_coll_inter_allgatherv_inter(const void *sbuf, int scount,
 {
     int i, rank, size, size_local, total=0, err;
     int *count=NULL,*displace=NULL;
-    char *ptmp_free=NULL, *ptmp;
+    char *ptmp_free=NULL, *ptmp=NULL;
     ompi_datatype_t *ndtype = NULL;
     ompi_request_t *req[2];
 

ompi/mca/coll/inter/coll_inter_gather.c

@@ -62,7 +62,7 @@ mca_coll_inter_gather_inter(const void *sbuf, int scount,
         ptrdiff_t gap, span;
 
         size_local = ompi_comm_size(comm->c_local_comm);
-        span = opal_datatype_span(&sdtype->super, scount*size_local, &gap);
+        span = opal_datatype_span(&sdtype->super, (int64_t)scount*(int64_t)size_local, &gap);
 
         ptmp_free = (char*)malloc(span);
         if (NULL == ptmp_free) {

ompi/mca/coll/inter/coll_inter_gatherv.c

@@ -46,7 +46,7 @@ mca_coll_inter_gatherv_inter(const void *sbuf, int scount,
 {
     int i, rank, size, size_local, total=0, err;
     int *count=NULL, *displace=NULL;
-    char *ptmp_free=NULL, *ptmp;
+    char *ptmp_free=NULL, *ptmp=NULL;
     ompi_datatype_t *ndtype;
 
     if (MPI_PROC_NULL == root) { /* do nothing */

ompi/mca/coll/inter/coll_inter_scatter.c

@@ -56,13 +56,13 @@ mca_coll_inter_scatter_inter(const void *sbuf, int scount,
         err = OMPI_SUCCESS;
     } else if (MPI_ROOT != root) {
         /* First process receives the data from root */
-        char *ptmp_free = NULL, *ptmp;
+        char *ptmp_free = NULL, *ptmp = NULL;
 	if(0 == rank) {
             int size_local;
             ptrdiff_t gap, span;
 
 	    size_local = ompi_comm_size(comm->c_local_comm);
-            span = opal_datatype_span(&rdtype->super, rcount*size_local, &gap);
+            span = opal_datatype_span(&rdtype->super, (int64_t)rcount*(int64_t)size_local, &gap);
             ptmp_free = malloc(span);
 	    if (NULL == ptmp_free) {
 		return OMPI_ERR_OUT_OF_RESOURCE;

ompi/mca/coll/inter/coll_inter_scatterv.c

@@ -47,7 +47,7 @@ mca_coll_inter_scatterv_inter(const void *sbuf, const int *scounts,
 {
     int i, rank, size, err, total=0, size_local;
     int *counts=NULL,*displace=NULL;
-    char *ptmp_free=NULL, *ptmp;
+    char *ptmp_free=NULL, *ptmp=NULL;
     ompi_datatype_t *ndtype;
 
     /* Initialize */

ompi/mca/coll/libnbc/nbc_iexscan.c

@@ -72,9 +72,9 @@ int ompi_coll_libnbc_iexscan(const void* sendbuf, void* recvbuf, int count, MPI_
             return OMPI_ERR_OUT_OF_RESOURCE;
         }
         if (inplace) {
-            NBC_Copy(recvbuf, count, datatype, (char *)handle->tmpbuf-gap, count, datatype, comm);
+            res = NBC_Copy(recvbuf, count, datatype, (char *)handle->tmpbuf-gap, count, datatype, comm);
         } else {
-            NBC_Copy(sendbuf, count, datatype, (char *)handle->tmpbuf-gap, count, datatype, comm);
+            res = NBC_Copy(sendbuf, count, datatype, (char *)handle->tmpbuf-gap, count, datatype, comm);
         }
         if (OPAL_UNLIKELY(OMPI_SUCCESS != res)) {
             NBC_Return_handle (handle);