fib_trie: leaf_walk_rcu should not compute key if key is less than pn->key
fib_trie: leaf_walk_rcu should not compute key if key is less than pn->key

We were computing the child index in cases where the key value we were
looking for was actually less than the base key of the tnode.  As a result
we were getting incorrect index values that would cause us to skip over
some children.

To fix this I have added a test that will force us to use child index 0 if
the key we are looking for is less than the key of the current tnode.

Fixes: 8be33e955cb9 ("fib_trie: Fib walk rcu should take a tnode and key instead of a trie and a leaf")
Reported-by: Brian Rak <26542f042da3c673ae2ae070265b6d8bf2368646@gameservers.com>
Signed-off-by: Alexander Duyck <65fbf386e60e512f5266151fdc208e509cb2778b@mirantis.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs