selinux: fix broken peer recv check

commit 46d01d63221c3508421dd72ff9c879f61053cffc upstream.

Fix a broken networking check. Return an error if peer recv fails.  If
secmark is active and the packet recv succeeds the peer recv error is
ignored.

Signed-off-by: Chad Hanson <chanson@trustedcs.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>