SWDEV-330307 - Avoid releasing command before last use

The fix for SWDEV-329789 moved down the last use of the a
command object pointer in order to prevent a race condition.
However, the previous patch did not move down the release of
that command. By releasing the command early, another thread
could get a command with the same pointer. That second thread
could later submit work to the queue using that new command.
The first thread could then perform a comparison against the
queue's last command using its own now-stale pointer. This
could eventually allow the second thread to skip synchornizing
on the queue. This would result in host synchronizations
completing before their device work was actually complete.

Change-Id: I292b7b369743251ceafe453a4c5cae14a6d01046


[ROCm/clr commit: 6b956f7627]

projects/clr/rocclr/platform/commandqueue.cpp

@@ -136,7 +136,6 @@ void HostQueue::finish() {
     ClPrint(LOG_DEBUG, LOG_CMD, "HW Event not ready, awaiting completion instead");
     command->awaitCompletion();
   }
-  command->release();
   if (IS_HIP) {
     ScopedLock sl(vdev()->execution());
     ScopedLock l(lastCmdLock_);
@@ -146,6 +145,7 @@ void HostQueue::finish() {
       lastEnqueueCommand_ = nullptr;
     }
   }
+  command->release();
   ClPrint(LOG_DEBUG, LOG_CMD, "All commands finished");
 }