xfree86: ensure the readlink buffer is null-terminated

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Dave Airlie <airlied@redhat.com>
1 job for wip/coverity-fixes in 1 minute and 59 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #29785
job

00:01:59