tipc: remove redundant code in topology server

The socket handling in the topology server is unnecessarily generic.
It is prepared to handle both SOCK_RDM, SOCK_DGRAM and SOCK_STREAM
type sockets, as well as the only socket type which is really used,
SOCK_SEQPACKET.

We now remove this redundant code to make the code more readable.

Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>