i965: Drop a funny assert about mt pitch.

I slipped this in in the region->pitch change from pixels to bytes, but I
don't see any reason for it any more -- the libdrm code doesn't appear to
divide pitch by a cpp.

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

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

@@ -140,7 +140,6 @@ aub_dump_bmp(struct gl_context *ctx)
 	    continue;
 	 }
 
-         assert(irb->mt->pitch % irb->mt->cpp == 0);
          drm_intel_gem_bo_aub_dump_bmp(irb->mt->bo,
 				       irb->draw_x,
 				       irb->draw_y,