sctp: eliminate useless code

Remove duplicate declaration of symbol: struct hlist_node *node was
already declared, the seconds declaration shadows the first one.

CC: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
Signed-off-by: David S. Miller <davem@davemloft.net>