i965: Fix incorrect comment about single program flow on Ironlake.
i965: Fix incorrect comment about single program flow on Ironlake.

The code forces single program flow to be enabled on Ironlake, or
equivalently, disables multiple program flow.  The comment was reversed.

Signed-off-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Reviewed-by: Eric Anholt <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@anholt.net>

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