Fix a logic error in the SACK list cleanup causing a memleak and invalid memory access at the same time.

src/stream-tcp-sack.c

@@ -328,7 +328,7 @@ void StreamTcpSackFreeList(TcpStream *stream) {
 
     while (rec != NULL) {
         next = rec->next;
-        SCFree(next);
+        SCFree(rec);
         rec = next;
     }