sctp: remove 'resent' bit from the chunk

The 'resent' bit is used to make sure that we don't update
rto estimate based on retransmitted chunks.  However, we already
have the 'rto_pending' bit that we test when need to update rto,
so 'resent' bit is just extra.  Additionally, we currently have
a bug in that we always set a 'resent' bit and thus rto estimate
is only updated by Heartbeats.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
diff --git a/net/sctp/output.c b/net/sctp/output.c
index fad261d..35e49b9 100644
--- a/net/sctp/output.c
+++ b/net/sctp/output.c
@@ -429,24 +429,17 @@
 	list_for_each_entry_safe(chunk, tmp, &packet->chunk_list, list) {
 		list_del_init(&chunk->list);
 		if (sctp_chunk_is_data(chunk)) {
+			/* 6.3.1 C4) When data is in flight and when allowed
+			 * by rule C5, a new RTT measurement MUST be made each
+			 * round trip.  Furthermore, new RTT measurements
+			 * SHOULD be made no more than once per round-trip
+			 * for a given destination transport address.
+			 */
 
-			if (!chunk->resent) {
-
-				/* 6.3.1 C4) When data is in flight and when allowed
-				 * by rule C5, a new RTT measurement MUST be made each
-				 * round trip.  Furthermore, new RTT measurements
-				 * SHOULD be made no more than once per round-trip
-				 * for a given destination transport address.
-				 */
-
-				if (!tp->rto_pending) {
-					chunk->rtt_in_progress = 1;
-					tp->rto_pending = 1;
-				}
+			if (!tp->rto_pending) {
+				chunk->rtt_in_progress = 1;
+				tp->rto_pending = 1;
 			}
-
-			chunk->resent = 1;
-
 			has_data = 1;
 		}