tipc: remove tsk->connected for connectionless sockets

Until now, for connectionless sockets the peer information during
connect is stored in tsk->peer and a connection state is set in
tsk->connected. This is redundant.

In this commit, for connectionless sockets we update:
- __tipc_sendmsg(), when the destination is NULL the peer existence
  is determined by tsk->peer.family, instead of tsk->connected.
- tipc_connect(), remove set/unset of tsk->connected.
Hence tsk->connected is no longer used for connectionless sockets.

There is no functional change in this commit.

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