Revert "[PATCH] Enforce "unsigned long flags;" when spinlocking"

This reverts commit ee3ce191, since it
broke on at least ARM, MIPS and PA-RISC due to complicated header file
dependencies.

Conflicts in include/linux/spinlock.h (due to the "nested" variety
fixes) fixed up by hand.

Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@parisc-linux.org>
Cc: Russell King <rmk+lkml@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>