i965: Fix tex_swizzle when depth mode is GL_RED

Change swizzle from (x000) to (x001).

Signed-off-by: Chad Versace <chad.versace@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/mesa/drivers/dri/i965/brw_wm.c

@@ -377,9 +377,10 @@ static void brw_wm_populate_key( struct brw_context *brw,
 	    } else if (t->DepthMode == GL_LUMINANCE) {
 	       swizzles[3] = SWIZZLE_ONE;
 	    } else if (t->DepthMode == GL_RED) {
+	       /* See table 3.23 of the GL 3.0 spec. */
 	       swizzles[1] = SWIZZLE_ZERO;
 	       swizzles[2] = SWIZZLE_ZERO;
-	       swizzles[3] = SWIZZLE_ZERO;
+	       swizzles[3] = SWIZZLE_ONE;
 	    }
 	 }