Update to libsepol 2.2.

Update to current upstream libsepol release.
Includes memory leak fixes, improved handling of filename-based
type transitions, and support for latest kernel policy version.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

(cherry picked from commit dedcd596b31e0e4fc15d75b3a8b5e6b61e6c28b3)

Change-Id: I273e3aac223d25c918f71d566ea752b64ec59cd7