[PATCH] m68k: adjust to changed HARDIRQ_MASK

Adjust entry.S to the changed HARDIRQ_MASK, add a check to prevent it from
silently breaking again.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>