Check return code for Flush operation

Current NCCL code does not abort for failed Flush operations by
underlying network. This may compromise data integrity.

Signed-off-by: Rashika Kheria <rashika@amazon.com>


[ROCm/rccl commit: 6c61492eba]

projects/rccl/src/transport/net.cc

@@ -378,7 +378,7 @@ ncclResult_t netRecvProxy(struct ncclProxyArgs* args) {
         if (done) {
           args->head += args->sliceSteps;
           if (args->protocol == NCCL_PROTO_SIMPLE) {
-            if (resources->useGdr) ncclNetFlush(resources->netRecvComm, localBuff+buffSlot*stepSize, size, mhandle);
+            if (resources->useGdr) NCCLCHECK(ncclNetFlush(resources->netRecvComm, localBuff+buffSlot*stepSize, size, mhandle));
             resources->hostRecvMem->tail = args->head;
           }
           args->idle = 0;