input: replace spin_lock_bh with spin_lock_irqsave in ml_ff_playback
ml_ff_playback() uses spin_(un)lock_bh. However this function is called
with interrupts disabled from erase_effect() in drivers/input/ff-core.c:196.
This is not permitted, and will result in a WARN_ON in the bottom half handling code.
This patch changes this function to just use spin_lock_irqsave() instead, solving
the problem and simplifying the locking logic.
This was reported as entry #106559 in kerneloops.org
Reported-by: kerneloops.org Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>