mesa/st: Fix image selection for blit soruces.
If the texture hasn't yet been validated, the current tex image contents may have been ignored in favor of the texture's main miptree. Fixes test failure on softpipe in:
Cc: mesa-stable
Due to an influx of spam, we have had to impose restrictions on new accounts. Please see this wiki page for instructions on how to get full permissions. Sorry for the inconvenience.
If the texture hasn't yet been validated, the current tex image contents may have been ignored in favor of the texture's main miptree. Fixes test failure on softpipe in:
Cc: mesa-stable