nir_to_tgsi: Fix indices for CMP in nir_to_tgsi for nir_op_fcsel
nir_to_tgsi utiliy was using wrong src for nir_op_fcsel.
Fixes regression with solidworks2012_viewport.trace and mudbox-2010sp1-basic-head.trace
v2: as per suggested by Brian, instead of relying assumption that value will be 0.0 or 1.0 all the time, use -abs(src) to make any non-zero value as negative.
Reviewed-by: Brian Paul brianp@vmware.com Reviewed-by: Charmaine Lee charmainel@vmware.com