tipc: fix rebasing error

In commit 2f487712 ("tipc: guarantee that group broadcast doesn't
bypass group unicast") there was introduced a last-minute rebasing
error that broke non-group communication.

We fix this here.

Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>