[PATCH] remove the second arg of do_timer_interrupt()

The second arg of do_timer_interrupt() is not used in the functions, and
all callers pass NULL.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Paul Mundt <lethal@Linux-SH.ORG>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>