[PATCH] prototypes for *at functions & typo fix

Here's the follow-up patch which introduces the prototypes for the new
syscalls.  There was also a typo in one of the new symbols.

Signed-off-by: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>