tipc: fix bug during lookup of multicast destination nodes

In commit 232d07b7

 ("tipc: improve groupcast scope handling") we
inadvertently broke non-group multicast transmission when changing the
parameter 'domain' to 'scope' in the function
tipc_nametbl_lookup_dst_nodes(). We missed to make the corresponding
change in the calling function, with the result that the lookup always
fails.

A closer anaysis reveals that this parameter is not needed at all.
Non-group multicast is hard coded to use CLUSTER_SCOPE, and in the
current implementation this will be delivered to all matching
destinations except those which are published with NODE_SCOPE on other
nodes. Since such publications never will be visible on the sending node
anyway, it makes no sense to discriminate by scope at all.

We now remove this parameter altogether.

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