Revert "selinux: fix the default socket labeling in sock_graft()"

This reverts commit 4da6daf4.

Unfortunately, the commit in question caused problems with Bluetooth
devices, specifically it caused them to get caught in the newly
created BUG_ON() check.  The AF_ALG problem still exists, but will be
addressed in a future patch.

Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>