MINOR: stream: Uninline and export sess_set_term_flags() function

This function will be used to set termination flags on TCP streams from
outside of process_stream(). Thus, it must be uninlined and exported.
diff --git a/src/stream.c b/src/stream.c
index ae92b18..f8fc062 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -960,7 +960,7 @@
  * also counts a failed request if the server state has not reached the request
  * stage.
  */
-static void sess_set_term_flags(struct stream *s)
+void sess_set_term_flags(struct stream *s)
 {
 	if (!(s->flags & SF_FINST_MASK)) {
 		if (s->scb->state == SC_ST_INI) {