kfdtest: fix event leaks issue

DisableCpQueueByUpdateWithZeroPercentage need to destroy event to avoid
event leak.

Signed-off-by: Emily Deng <Emily.Deng@amd.com>
Change-Id: I4fb51b670fbff1edcd7fd61517f5c8a6674003c0


[ROCm/ROCR-Runtime commit: 1f9c080932]

projects/rocr-runtime/libhsakmt/tests/kfdtest/src/KFDQMTest.cpp

@@ -578,6 +578,7 @@ TEST_F(KFDQMTest, DisableCpQueueByUpdateWithZeroPercentage) {
     queue.Wait4PacketConsumption(event);
 
     WaitOnValue(destBuf.As<unsigned int*>(), 1);
+    hsaKmtDestroyEvent(event);
 
     EXPECT_SUCCESS(queue.Destroy());