Cleanup sync object handling in ompi_request_complete

It's sufficient to swap the req_complete with REQUEST_COMPLETED
and look at the original value to decide whether a sync object was
there. No need to first CAS and then swap.

Signed-off-by: Joseph Schuchart <schuchart@icl.utk.edu>

Author: devreal

ompi/request/request.h

@@ -537,18 +537,16 @@ static inline int ompi_request_complete(ompi_request_t* request, bool with_signa
     }
 
     if (0 == rc) {
-        if( OPAL_LIKELY(with_signal) ) {
-            void *_tmp_ptr = REQUEST_PENDING;
-
-            if(!OPAL_ATOMIC_COMPARE_EXCHANGE_STRONG_PTR(&request->req_complete, &_tmp_ptr, REQUEST_COMPLETED)) {
-                ompi_wait_sync_t *tmp_sync = (ompi_wait_sync_t *) OPAL_ATOMIC_SWAP_PTR(&request->req_complete,
-                                                                                       REQUEST_COMPLETED);
-                /* In the case where another thread concurrently changed the request to REQUEST_PENDING */
-                if( REQUEST_PENDING != tmp_sync )
-                    wait_sync_update(tmp_sync, 1, request->req_status.MPI_ERROR);
+        if (OPAL_LIKELY(with_signal)) {
+
+            ompi_wait_sync_t *tmp_sync = (ompi_wait_sync_t *) OPAL_ATOMIC_SWAP_PTR(&request->req_complete,
+                                                                                    REQUEST_COMPLETED);
+            if( REQUEST_PENDING != tmp_sync ) {
+                wait_sync_update(tmp_sync, 1, request->req_status.MPI_ERROR);
             }
-        } else
+        } else {
             request->req_complete = REQUEST_COMPLETED;
+        }
     }
 
     return OMPI_SUCCESS;