libsepol: Report all neverallow violations.

Switch libsepol check_assertions() from only reporting the first violation
to reporting them all.

Change-Id: I45b3502ff96b1d093574e1fecff93a582f8d00bd
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Steve Lawrence <slawrence@tresys.com>
Fix expand logic for policy versions older than 24.

This was broken for older policy versions when we updated to
version 24.

Broken by commit 787f2f00f5d8ed6f5f.

Change-Id: I4063334c5c0462ef5c3706611c7dff5c60c612aa
Reported-by: William Roberts <bill.c.roberts@gmail.com>
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>