stub: remove unnecessary condition in if statement (#12437)

This PR removes unnecessary condition inside an `if` statement in
BlockingClientCall class.
There is no functional change.

Fixes #12425

Author: becomeStar

stub/src/main/java/io/grpc/stub/BlockingClientCall.java

@@ -225,7 +225,7 @@ private boolean write(boolean waitForever, ReqT request, long endNanoTime)
         (x) -> x.call.isReady() || x.closeState.get() != null;
     executor.waitAndDrainWithTimeout(waitForever, endNanoTime, predicate, this);
     CloseState savedCloseState = closeState.get();
-    if (savedCloseState == null || savedCloseState.status == null) {
+    if (savedCloseState == null) {
       call.sendMessage(request);
       return true;
     } else if (savedCloseState.status.isOk()) {