OSHMEM: fixes crash during initialization

Do not call mpi comm_dup() if mpi failed to initialize. Also do not set
signal handlers.
Small code styling fixes.

Signed-off-by: Alex Mikheev <alexm@mellanox.com>

oshmem/runtime/oshmem_shmem_init.c

@@ -149,13 +149,17 @@ int oshmem_shmem_init(int argc, char **argv, int requested, int *provided)
         if (!ompi_mpi_initialized && !ompi_mpi_finalized) {
             ret = ompi_mpi_init(argc, argv, requested, provided);
         }
-        PMPI_Comm_dup(MPI_COMM_WORLD, &oshmem_comm_world);
 
-        if (OSHMEM_SUCCESS == ret) {
-            ret = _shmem_init(argc, argv, requested, provided);
+        if (OSHMEM_SUCCESS != ret) {
+            return ret;
         }
 
-        if (OSHMEM_SUCCESS == ret) {
+        PMPI_Comm_dup(MPI_COMM_WORLD, &oshmem_comm_world);
+        ret = _shmem_init(argc, argv, requested, provided);
+
+        if (OSHMEM_SUCCESS != ret) {
+            return ret;
+        }
         oshmem_shmem_initialized = true;
 
         if (OSHMEM_SUCCESS != shmem_lock_init()) {
@@ -171,14 +175,12 @@ int oshmem_shmem_init(int argc, char **argv, int requested, int *provided)
         pthread_t thread_id;
         int perr;
         perr = pthread_create(&thread_id, NULL, &shmem_opal_thread, NULL);
-            if (perr != 0)
-            {
+        if (0 != perr) {
             SHMEM_API_ERROR("cannot creat opal thread for SHMEM");
             return OSHMEM_ERROR;
         }
 #endif
     }
-    }
 #ifdef SIGUSR1
     signal(SIGUSR1,sighandler__SIGUSR1);
     signal(SIGTERM,sighandler__SIGTERM);