If we switch extern inline to static inline, we'd better switch the
pre-declarations we use to say that these puppies have
__attribute_const__ on them.

Otherwise we get extern declaration followed by static inline one.
Which makes gcc unhappy, and for a good reason...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>