[PATCH] knfsd: Fix type mismatch with filldir_t used by nfsd

nfsd defines a type 'encode_dent_fn' which is much like 'filldir_t' except
that the first pointer is 'struct readdir_cd *' rather than 'void *'.  It
then casts encode_dent_fn points to 'filldir_t' as needed.  This hides any
other type mismatches between the two such as the fact that the 'ino' arg
recently changed from ino_t to u64.

So: get rid of 'encode_dent_fn', get rid of the cast of the function type,
change the first arg of various functions from 'struct readdir_cd *' to
'void *', and live with the fact that we have a little less type checking
on the calling of these functions now.  Less internal (to nfsd) checking
offset by more external checking, which is more important.

Thanks to Gabriel Paubert <paubert@iram.es> for discovering this and
providing an initial patch.

Signed-off-by: Gabriel Paubert <paubert@iram.es>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>