ip-address: constify match_link_kind arg

Since the function won't ever change the data 'kind' is pointing at, it
can sanely be made const.

Fixes: e0513807f6dbb ("ip-address: Support filtering by slave type, too")
Suggested-by: Stephen Hemminger <shemming@brocade.com>
Signed-off-by: Phil Sutter <phil@nwl.cc>
1 file changed