Update to libsepol 2.1.8.

Change-Id: I7d848ee312d4c706162a822d2031f37a5557ed5f
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Fix memory leak issues found by Klocwork

Change-Id: If324d424dc11df435c26b0da11e314c7608180f9