minijail: use %m instead of strerror

Use the GNU %m extension to display the errno string.  This makes
the code a bit smaller and fixes build errors where util.h doesn't
include errno.h itself.

BUG=None
TEST=ran minijail w/-p as non-root and checked error log included errno decoded

Change-Id: I104e2e8092ecae1f77951c2f67c7b34bf9eff6a7
Reviewed-on: https://chromium-review.googlesource.com/239841
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed