rhashtable: Rip out obsolete out-of-line interface

Now that all rhashtable users have been converted over to the
inline interface, this patch removes the unused out-of-line
interface.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc include/linux/rhashtable.h
Simple merge

diff --cc lib/rhashtable.c
Simple merge