Revert "selinux: call WARN_ONCE() instead of calling audit_log_start()"

This reverts commit a4f9ef44ce771ea5ef982162280ecb5c8f9cbcf5.
Revert "SELinux: Fix memory leak upon loading policy"

This reverts commit 386223b3c5c0862852ad978b928b370ec29d3f58.