fib_trie: Remove leaf_info

At this point the leaf_info hash is redundant.  By adding the suffix length
to the fib_alias hash list we no longer have need of leaf_info as we can
determine the prefix length from fa_slen.  So we can compress things by
dropping the leaf_info structure from fib_trie and instead directly connect
the leaves to the fib_alias hash list.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>