lavapipe: fix array texture region copies
these need to use different struct members for copying array textures
the buffer2image variants are already doing the right thing
Fixes: b38879f8 ("vallium: initial import of the vulkan frontend")
these need to use different struct members for copying array textures
the buffer2image variants are already doing the right thing
Fixes: b38879f8 ("vallium: initial import of the vulkan frontend")