layers: Repro and fix GH 2239
layers: Repro and fix GH 2239

Modified positive test UncompressedToCompressedImageCopy to provoke
the issue reported in GH 2239

Fixed destination extents calculations in buffer_validation.cpp to
avoid the erroneous errors

Change-Id: I268f14a6be678d767df14f0a6694aca479854c3

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