ipc: lost unlock and fput in mqueue.c on error path

The error path in sys_mq_getsetattr() after the call to
audit_mq_getsetattr() is wrong - the info->lock is not unlocked and the
struct file *filp is not put.

Fix them both.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Cc: Pierre Peiffer <pierre.peiffer@bull.net>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>