Staging: batman-adv: unify orig_hash_lock spinlock handling to avoid deadlocks

The orig_hash_lock spinlock always has to be locked with IRQs being
disabled to avoid deadlocks between code that is being executed in
IRQ context and code that is being executed in non-IRQ context.

Reported-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>