Fix merge issues in memory unit tests (#123)

[ROCm/hip-tests commit: 75bb521e18]

projects/hip-tests/catch/unit/memory/hipMemGetAddressRange.cc

@@ -74,7 +74,7 @@ TEST_CASE("Unit_hipMemGetAddressRange_Negative") {
   const int offset = kPageSize;
   LinearAllocGuard<int> host_alloc(LinearAllocs::hipHostMalloc, allocation_size);
 
-  hipDeviceptr_t dummy_ptr;
+  hipDeviceptr_t dummy_ptr = NULL;
 
   SECTION("Device pointer is invalid") {
     HIP_CHECK_ERROR(hipMemGetAddressRange(&base_ptr, &mem_size, dummy_ptr), hipErrorNotFound);