Remove "signed vs. unsigned" warnings.

opal/mca/btl/tcp/btl_tcp.c

@@ -94,7 +94,7 @@ int mca_btl_tcp_add_procs( struct mca_btl_base_module_t* btl,
 
         OPAL_THREAD_LOCK(&tcp_proc->proc_lock);
 
-        for (int j = 0 ; j < (int)tcp_proc->proc_endpoint_count ; ++j) {
+        for (uint32_t j = 0 ; j < (int)tcp_proc->proc_endpoint_count ; ++j) {
             tcp_endpoint = tcp_proc->proc_endpoints[j];
             if (tcp_endpoint->endpoint_btl == tcp_btl) {
                 existing_found = true;

opal/mca/btl/tcp/btl_tcp_proc.c

@@ -768,7 +768,7 @@ mca_btl_tcp_proc_t* mca_btl_tcp_proc_lookup(const opal_process_name_t *name)
         }
 
         /* try adding this proc to each btl until */
-        for (int i = 0 ; i < (int)mca_btl_tcp_component.tcp_num_btls ; ++i) {
+        for( uint32_t i = 0; i < mca_btl_tcp_component.tcp_num_btls; ++i ) {
             endpoint = NULL;
             (void) mca_btl_tcp_add_procs (&mca_btl_tcp_component.tcp_btls[i]->super, 1, &opal_proc,
                                           &endpoint, NULL);