mesa: Check for vertex program the same way in desktop GL and ES

mesa: Check for vertex program the same way in desktop GL and ES

On Bay Trail-D using Fedora 20 compile flags (-m64 -O2 -mtune=generic
for 64-bit and -m32 -march=i686 -mtune=atom for 32-bit), affects
Gl32Multithread:

32-bit: Difference at 95.0% confidence 0.416027% +/- 0.163529% (n=40)
64-bit: Difference at 95.0% confidence 0.494771% +/- 0.259985% (n=40)

Gl32Batch7 had no difference proven at 95.0% confidence (n=120) on
32-bit or 64-bit.

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>