executor: fix unexpected mpp grpc EOF error log (#50010)

close #50011

Author: guo-shaoge

pkg/executor/internal/mpp/local_mpp_coordinator.go

@@ -519,12 +519,13 @@ func (c *localMppCoordinator) receiveResults(req *kv.MPPDispatchRequest, taskMet
 
 		resp, err = stream.Recv()
 		if err != nil {
-			logutil.BgLogger().Info("mpp stream recv got error", zap.Error(err), zap.Uint64("timestamp", taskMeta.StartTs),
-				zap.Int64("task", taskMeta.TaskId), zap.Int64("mpp-version", taskMeta.MppVersion))
 			if errors.Cause(err) == io.EOF {
 				return
 			}
 
+			logutil.BgLogger().Info("mpp stream recv got error", zap.Error(err), zap.Uint64("timestamp", taskMeta.StartTs),
+				zap.Int64("task", taskMeta.TaskId), zap.Int64("mpp-version", taskMeta.MppVersion))
+
 			// if NeedTriggerFallback is true, we return timeout to trigger tikv's fallback
 			if c.needTriggerFallback {
 				c.sendError(derr.ErrTiFlashServerTimeout)