fix GL_DOT3_RGBA texture combiner mode in generated fragment programs (bug #11030)

src/mesa/main/texenvprogram.c

@@ -871,7 +871,7 @@ emit_texenv(struct texenv_fragment_program *p, GLuint unit)
 			  key->unit[unit].OptRGB);
    }
    else if (key->unit[unit].ModeRGB == MODE_DOT3_RGBA_EXT ||
-	    key->unit[unit].ModeA == MODE_DOT3_RGBA) {
+	    key->unit[unit].ModeRGB == MODE_DOT3_RGBA) {
 
       out = emit_combine( p, dest, WRITEMASK_XYZW, saturate,
 			  unit,