(hipStreamDestory)Memory Leak Fix!!! Find by valgrind

[takohack]

bool HostQueue::terminate() {
.....
// Wake-up the command loop, so it can exit
    {
      ScopedLock sl(queueLock_);
      thread_.acceptingCommands_ = false;
      queueLock_.notify();
    }
// FIXME_lmoriche: fix termination handshake
    while (thread_.state() < Thread::FINISHED) {
      Os::yield();
    }

// Release last enque command !! Memory leak
if (lastEnqueueCommand_ != nullptr) {
      lastEnqueueCommand_->release();
      lastEnqueueCommand_ = nullptr;
    }

}

[takohack]

My Test

int main() {
  hipStream_t stream;
  hipStreamCreate(&stream);
  hipStreamDestroy(stream);
}