Revert commit c846ef7deba2 ("include/linux/smp.h:on_each_cpu(): switch
back to a macro"). It turns out that the problematic linux/irqflags.h
include was fixed within ia64 and mn10300.
Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>