r600g: Simplify out a couple of unnecessary branches
r600g: Simplify out a couple of unnecessary branches

Signed-off-by: Edward O'Callaghan <117173807d5a49976a891944633465c0daea7f98@alterapraxis.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler