sctp: Remove some redundant code

In commit 311b2177

 ("sctp: simplify sk_receive_queue locking"), a call
to 'skb_queue_splice_tail_init()' has been made explicit. Previously it was
hidden in 'sctp_skb_list_tail()'

Now, the code around it looks redundant. The '_init()' part of
'skb_queue_splice_tail_init()' should already do the same.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>