kfdtest: Hotfix wrong isaBuffer used in DeviceHdpFlush

In DeviceHdpFlush, isaBuffer was accidentally used instead of isaBuffer0
during LLVM re-work--revert.

Signed-off-by: Graham Sider <Graham.Sider@amd.com>
Change-Id: I98d2322e772f821a39505bb336ceb4e6cd8722ef

tests/kfdtest/src/KFDMemoryTest.cpp

@@ -1879,7 +1879,7 @@ TEST_F(KFDMemoryTest, DeviceHdpFlush) {
     ASSERT_SUCCESS(queue0.Create(nodes[1]));
     HsaMemoryBuffer isaBuffer0(PAGE_SIZE, nodes[1], true/*zero*/, false/*local*/, true/*exec*/);
 
-    ASSERT_SUCCESS(m_pAsm->RunAssembleBuf(WriteAndSignalIsa, isaBuffer.As<char*>()));
+    ASSERT_SUCCESS(m_pAsm->RunAssembleBuf(WriteAndSignalIsa, isaBuffer0.As<char*>()));
 
     Dispatch dispatch0(isaBuffer0);
     dispatch0.SetArgs(buffer, mmioBase);