Fixed -Werror=unused-result warnings in comm_cid.c by adding error checking

Signed-off-by: Joshua Gerrard <enquiries@joshuagerrard.com>
Signed-off-by: Jeff Squyres <jsquyres@cisco.com>

(cherry picked from commit 7cf5de1)

Author: OMGtechy

ompi/communicator/comm_cid.c

@@ -840,6 +840,9 @@ static int ompi_comm_allreduce_pmix_reduce_complete (ompi_comm_request_t *reques
     opal_pmix_pdata_t pdat;
     opal_buffer_t sbuf;
     int rc;
+    int bytes_written;
+    const int output_id = 0;
+    const int verbosity_level = 1;
 
     OBJ_CONSTRUCT(&sbuf, opal_buffer_t);
 
@@ -858,16 +861,36 @@ static int ompi_comm_allreduce_pmix_reduce_complete (ompi_comm_request_t *reques
     opal_dss.unload(&sbuf, (void**)&info.data.bo.bytes, &info.data.bo.size);
     OBJ_DESTRUCT(&sbuf);
 
-    if (cid_context->send_first) {
-        (void)asprintf(&info.key, "%s:%s:send:%d", cid_context->port_string, cid_context->pmix_tag,
-                       cid_context->iter);
-        (void)asprintf(&pdat.value.key, "%s:%s:recv:%d", cid_context->port_string, cid_context->pmix_tag,
-                       cid_context->iter);
+    bytes_written = asprintf(&info.key,
+                             cid_context->send_first ? "%s:%s:send:%d"
+                                                     : "%s:%s:recv:%d",
+                             cid_context->port_string,
+                             cid_context->pmix_tag,
+                             cid_context->iter);
+
+    if (bytes_written == -1) {
+        opal_output_verbose (verbosity_level, output_id, "writing info.key failed\n");
     } else {
-        (void)asprintf(&info.key, "%s:%s:recv:%d", cid_context->port_string, cid_context->pmix_tag,
-                       cid_context->iter);
-        (void)asprintf(&pdat.value.key, "%s:%s:send:%d", cid_context->port_string, cid_context->pmix_tag,
-                       cid_context->iter);
+        bytes_written = asprintf(&pdat.value.key,
+                                 cid_context->send_first ? "%s:%s:recv:%d"
+                                                         : "%s:%s:send:%d",
+                                 cid_context->port_string,
+                                 cid_context->pmix_tag,
+                                 cid_context->iter);
+
+        if (bytes_written == -1) {
+            opal_output_verbose (verbosity_level, output_id, "writing pdat.value.key failed\n");
+        }
+    }
+
+    if (bytes_written == -1) {
+        // write with separate calls,
+        // just in case the args are the cause of failure
+        opal_output_verbose (verbosity_level, output_id, "send first: %d\n", cid_context->send_first);
+        opal_output_verbose (verbosity_level, output_id, "port string: %s\n", cid_context->port_string);
+        opal_output_verbose (verbosity_level, output_id, "pmix tag: %s\n", cid_context->pmix_tag);
+        opal_output_verbose (verbosity_level, output_id, "iter: %d\n", cid_context->iter);
+        return OMPI_ERR_OUT_OF_RESOURCE;
     }
 
     /* this macro is not actually non-blocking. if a non-blocking version becomes available this function