Re: [libvirt] [PATCH] Don't chown qemu saved image back to root after save if dynamic_ownership=0

When dynamic_ownership=0, saved images must be owned by the same uid as is used to run the qemu process, otherwise restore won't work. To accomplish this, qemuSecurityDACRestoreSavedStateLabel() needs to simply return when it's called. This fix is in response to: https://bugzilla.redhat.com/show_bug.cgi?id=661720

--- Note that this still leaves open the issue discovered in this bug - if the saved image file already exists when it is "created" for the new save, whatever mode it has will be maintained, rather than forcing 0600. It would be simple to force the mode to 0600 (just add a flag to virFileOperation(), but I'm not sure if it would be safe to do so right now without a *lot* of testing (I'm concerned about possible scenarios where the chmod() that's done when the FORCE_PERMISSIONS flag is set might fail, making a previously working case fail). Any opinions on that? (At any rate, it should be done in a separate patch if we decide to do it).