mac80211: assign outgoing interface with nexthop

When updated mpath routing info is found, the new route
may be on a different interface (in the case of MBSS
sharing).

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
mac80211: hwmp: clear up matches_local_if

Clarify the API a bit by handing matches_local_if() the
MBSS to match against an address.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
mac80211: hwmp: clear up mesh_path_lookup() API

mesh_path_lookup() would take an sdata, but really search
the sdata list attached to the MBSS, so pass the MBSS
instead to make it clear the resulting mpath is tied to an
unknown interface.

This patch should have no functional changes.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>