sctp: remove macros sctp_{lock|release}_sock

Redefined {lock|release}_sock to sctp_{lock|release}_sock for user space friendly
code which we haven't use in years, so removing them.

Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>