Merge branch '271-uninitialized-size' into 'vulkan-cts-1.0'

Don't use uninitialized variables in dEQP-VK.api.copy_and_blit.buffer_to_image

The buffer to image test was using the uninitialized src image extent
for initializing the src buffer and the uninitialized dst buffer size
for initializing the dst image.

Fixes #271

See merge request !414