Merge branch 'sctp_do_bind-leak'

Mao Wenan says:

====================
fix memory leak for sctp_do_bind

First two patches are to do cleanup, remove redundant assignment,
and change return type of sctp_get_port_local.
Third patch is to fix memory leak for sctp_do_bind if failed
to bind address.

v2: add one patch to change return type of sctp_get_port_local.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>