[PATCH] kernel/acct: add kerneldoc

for kernel/acct.c:
- fix typos
- add kerneldoc for non-static functions

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>