i965/fs: Use a properly named constant in TXB handling.
i965/fs: Use a properly named constant in TXB handling.

The old value, BRW_SAMPLER_MESSAGE_SIMD8_SAMPLE makes it sound like we're
doing a non-bias texture lookup.  It has the same value as the new constant
BRW_SAMPLER_MESSAGE_SIMD8_SAMPLE_BIAS_COMPARE, so there should be no
functional changes.

dellis1972/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer,mcanthony/glsl-optimizer,metora/MesaGLSLCompiler,benaadams/glsl-optimizer,KTXSoftware/glsl2agal,zz85/glsl-optimizer,adobe/glsl2agal,tokyovigilante/glsl-optimizer,jbarczak/glsl-optimizer,dellis1972/glsl-optimizer,zeux/glsl-optimizer,bkaradzic/glsl-optimizer,adobe/glsl2agal,bkaradzic/glsl-optimizer,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,zeux/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer,tokyovigilante/glsl-optimizer,metora/MesaGLSLCompiler,benaadams/glsl-optimizer,jbarczak/glsl-optimizer,benaadams/glsl-optimizer,bkaradzic/glsl-optimizer,zz85/glsl-optimizer,djreep81/glsl-optimizer,mapbox/glsl-optimizer,mcanthony/glsl-optimizer,benaadams/glsl-optimizer,wolf96/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer,jbarczak/glsl-optimizer,zz85/glsl-optimizer,dellis1972/glsl-optimizer,dellis1972/glsl-optimizer,KTXSoftware/glsl2agal,zeux/glsl-optimizer,zeux/glsl-optimizer,dellis1972/glsl-optimizer,KTXSoftware/glsl2agal,tokyovigilante/glsl-optimizer,jbarczak/glsl-optimizer,metora/MesaGLSLCompiler,adobe/glsl2agal,benaadams/glsl-optimizer,mapbox/glsl-optimizer,tokyovigilante/glsl-optimizer,adobe/glsl2agal,jbarczak/glsl-optimizer,zeux/glsl-optimizer,KTXSoftware/glsl2agal,zz85/glsl-optimizer,wolf96/glsl-optimizer,djreep81/glsl-optimizer,djreep81/glsl-optimizer,djreep81/glsl-optimizer,mapbox/glsl-optimizer,KTXSoftware/glsl2agal,djreep81/glsl-optimizer,zz85/glsl-optimizer,zz85/glsl-optimizer,bkaradzic/glsl-optimizer,mapbox/glsl-optimizer,adobe/glsl2agal,benaadams/glsl-optimizer,mapbox/glsl-optimizer