i965: Get rid of intel_renderbuffer_resolve_*

i965: Get rid of intel_renderbuffer_resolve_*

There is exactly one caller so it's a bit pointless to have all of this
plumbing.  Just inline it at the one place it's used.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>
Reviewed-by: Chad Versace <chadversary@chromium.org>