Restore logging of pid= and comm= in AVC audit messages

We turned this all off because the 'exe=' was causing deadlocks on
dcache_lock. There's no need to leave the pid and comm out though. 
They'll all be logged correctly if full auditing is enabled, but we
should still print them in case auditing _isn't_ enabled.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>