link_is_up() and tipc_link_is_up() have the same functionality.
Consolidate these functions.
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Tung Nguyen <tung.q.nguyen@endava.com>
Signed-off-by: David S. Miller <davem@davemloft.net>