sctp: implement renege_events for sctp_stream_interleave

renege_events is added as a member of sctp_stream_interleave, used to
renege some old data or idata in reasm or lobby queue properly to free
some memory for the new data when there's memory stress.

It defines sctp_renege_events for idata, and leaves sctp_ulpq_renege
as it is for data.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
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>
diff --git a/net/sctp/sm_sideeffect.c b/net/sctp/sm_sideeffect.c
index f4e5eca..2bec17a 100644
--- a/net/sctp/sm_sideeffect.c
+++ b/net/sctp/sm_sideeffect.c
@@ -1735,8 +1735,9 @@ static int sctp_cmd_interpreter(enum sctp_event event_type,
 			break;
 
 		case SCTP_CMD_RENEGE:
-			sctp_ulpq_renege(&asoc->ulpq, cmd->obj.chunk,
-					 GFP_ATOMIC);
+			asoc->stream.si->renege_events(&asoc->ulpq,
+						       cmd->obj.chunk,
+						       GFP_ATOMIC);
 			break;
 
 		case SCTP_CMD_SETUP_T4: