kfifo: move out spinlock

kfifo: move out spinlock

Move the pointer to the spinlock out of struct kfifo.  Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.

Signed-off-by: Stefani Seibold <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Mauro Carvalho Chehab <[email protected]>
Acked-by: Andi Kleen <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>