Check for spurious wake ups

Condition::wait() can spuriously wake up, so we must guard it with
another check to ensure that a given wake was truly due to having
been signaled.

Bug: 34592766
Test: Boot bullhead
Change-Id: Iaa5a0ca6186aea50c51e2c402ef95d7ba861be92
diff --git a/libs/hwui/renderthread/RenderTask.cpp b/libs/hwui/renderthread/RenderTask.cpp
index b14f580..928a4ef 100644
--- a/libs/hwui/renderthread/RenderTask.cpp
+++ b/libs/hwui/renderthread/RenderTask.cpp
@@ -26,6 +26,7 @@
 void SignalingRenderTask::run() {
     mTask->run();
     mLock->lock();
+    mHasRun = true;
     mSignal->signal();
     mLock->unlock();
 }