[PATCH] selinux: Fix MLS compatibility off-by-one bug

Fix an off-by-one error in the MLS compatibility code that was causing
contexts with a MLS suffix to be rejected, preventing sharing partitions
between FC4 and FC5.  Bug reported in

   https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=188068

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>