Revert "sctp: fix call to SCTP_CMD_PROCESS_SACK in sctp_cmd_interpreter()"

This reverts commit b23270416da409bd4e637a5acbe31a1126235fb6 which is
commit f6e80abeab928b7c47cc1fbf53df13b4398a2bec.

Michal writes:
	Mainline commit f6e80abe was introduced in v3.7-rc2 as a
	follow-up fix to commit

	  edfee033  sctp: check src addr when processing SACK to update transport state

	(from v3.7-rc1) which changed the interpretation of third
	argument to sctp_cmd_process_sack() and sctp_outq_sack(). But as
	commit edfee033 has never been backported to stable branches,
	backport of commit f6e80abe actually breaks the code rather than
	fixing it.

Reported-by: Michal Kubecek <mkubecek@suse.cz>
Cc: Zijie Pan <zijie.pan@6wind.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Vlad Yasevich <vyasevich@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>