meta: Fix restoring of fixed function texture enables.

meta: Fix restoring of fixed function texture enables.

If they were disabled on entry, and we enabled one (like for
BlitFramebuffer), we wouldn't disable it on the way out.  Retain the
attempted optimization here (don't keep calling to set each bit for
changes that won't matter) by just setting the bits directly with
appropriate flushing.

Fixes misrendering on the second draw of piglit fbo-blit.

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>