We're presently getting oopses because Bluetooth (and possibly other) drivers
are calling core functions after things have been shut down.

So rather than oopsing, let's drop a warning then take avoiding action, so the
machine survives.  Once all the sub-drivers are fixed up we can remove the
take-avoiding-action part.
Signed-off-by: NPavel Machek <pavel@suse.cz>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>