loader: Fix debug report memory leaks
loader: Fix debug report memory leaks

Found a couple of memory leaks in the debug report code in the loader
while testing out allocators in cube.

Change-Id: I56b401394ca43bd8eb9b4f85baa52dfa597a6f49

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools