[PATCH] autofs4: use libfs routines for readdir

Change readdir routines to use the cursor based routines in libfs.c.  This
removes reliance on old readdir code from 2.4 and should improve efficiency of
readdir in autofs4.

Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>