[PATCH] Decrease number of pointer derefs in exit.c

Decrease the number of pointer derefs in kernel/exit.c

Benefits of the patch:
 - Fewer pointer dereferences should make the code slightly faster.
 - Size of generated code is smaller
 - improved readability

Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>