SELinux: change sbsec->behavior to short

We only have 6 options, so char is good enough, but use a short as that
packs nicely.  This shrinks the superblock_security_struct just a little
bit.

Signed-off-by: Eric Paris <eparis@redhat.com>

diff --cc security/selinux/include/objsec.h
Simple merge

diff --cc security/selinux/include/security.h
Simple merge

diff --cc security/selinux/ss/services.c
Simple merge