tcp_in : fix ooseq update error

if a pbuf received with the same seqno in ooseq ,
we then check  the size and replace the existing one
with the larger one,but if the existing one is the
last segment in ooseq ,it might has been trimed before.
the replacing action will overrun our receive windows

see patch #10106 and bug #56397

src/core/tcp_in.c

@@ -1687,6 +1687,15 @@ tcp_receive(struct tcp_pcb *pcb)
                  ->ooseq. We check the lengths to see which one to
                  discard. */
               if (inseg.len > next->len) {
+
+                /* If next segment is the last segment in ooseq
+                   and smaller than inseg, that means it has been
+                   trimmed before to fit our window, so we just
+                   break here. */
+                if (next->next == NULL) {
+                  break;
+                }
+
                 /* The incoming segment is larger than the old
                    segment. We replace some segments with the new
                    one. */