Revert "net:tipc: Fix a double free in tipc_sk_mcast_rcv"

This reverts commit 6bf24dc0.
Above fix is not correct and caused memory leak issue.

Fixes: 6bf24dc0 ("net:tipc: Fix a double free in tipc_sk_mcast_rcv")
Acked-by: Jon Maloy <jmaloy@redhat.com>
Acked-by: Tung Nguyen <tung.q.nguyen@dektech.com.au>
Signed-off-by: Hoang Le <hoang.h.le@dektech.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>