[PATCH] ecryptfs: use special_file()

Use the special_file() macro to check whether an inode is special instead of
open-coding it.

Acked-by: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>