The current calling conventions for ->follow_link() are already fairly
complex.

What we have is
	1) you can return -error; then you must release nameidata yourself
	   and ->put_link() will _not_ be called.
	2) you can do nd_set_link(nd, ERR_PTR(-error)) and return 0
	3) you can do nd_set_link(nd, path) and return 0
	4) you can return 0 (after having moved nameidata yourself)

jffs2 follow_link() is broken - it has an exit where it returns
-EIO and leaks nameidata.
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>