MINOR: stream-int: replace SI_FL_WANT_PUT with !SI_FL_RX_WAIT_EP

The SI_FL_WANT_PUT flag is used in an awkward way, sometimes it's
set by the stream-interface to mean "I have something to deliver",
sometimes it's cleared by the channel to say "I don't want you to
send what you have", and it has to be set back once CF_DONT_READ
is cleared. This will have to be split between SI_FL_RX_WAIT_EP
and SI_FL_RXBLK_CHAN. This patch only replaces all uses of the
flag with its natural (but negated) replacement SI_FL_RX_WAIT_EP.
The code is expected to be strictly equivalent. The now unused flag
was completely removed.
diff --git a/src/stream_interface.c b/src/stream_interface.c
index a4bbca5..bb1dc7a 100644
--- a/src/stream_interface.c
+++ b/src/stream_interface.c
@@ -225,7 +225,8 @@
 		/* Note that none of these states may happen with applets */
 		si->state = SI_ST_DIS;
 	default:
-		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_WANT_PUT | SI_FL_NOLINGER);
+		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_NOLINGER);
+		si->flags |= SI_FL_RX_WAIT_EP;
 		ic->flags &= ~CF_SHUTR_NOW;
 		ic->flags |= CF_SHUTR;
 		ic->rex = TICK_ETERNITY;
@@ -726,7 +727,7 @@
 	if (!(si->wait_event.wait_reason & SUB_CAN_RECV)) {
 		ret |= si_cs_recv(cs);
 		if (!(si_ic(si)->flags & (CF_SHUTR|CF_DONT_READ)))
-			si->flags |= SI_FL_WANT_PUT;
+			si->flags &= ~SI_FL_RX_WAIT_EP;
 	}
 	if (ret != 0)
 		si_cs_process(cs);
@@ -860,12 +861,12 @@
 	 * handled at the latest moment.
 	 */
 	if (obj_type(si_f->end) == OBJ_TYPE_APPCTX &&
-	    (((si_f->flags & (SI_FL_WANT_PUT|SI_FL_RXBLK_ROOM)) == SI_FL_WANT_PUT) ||
+	    (((si_f->flags & (SI_FL_RX_WAIT_EP|SI_FL_RXBLK_ROOM)) == 0) ||
 	     ((si_f->flags & (SI_FL_WANT_GET|SI_FL_WAIT_DATA)) == SI_FL_WANT_GET)))
 		appctx_wakeup(si_appctx(si_f));
 
 	if (obj_type(si_b->end) == OBJ_TYPE_APPCTX &&
-	    (((si_b->flags & (SI_FL_WANT_PUT|SI_FL_RXBLK_ROOM)) == SI_FL_WANT_PUT) ||
+	    (((si_b->flags & (SI_FL_RX_WAIT_EP|SI_FL_RXBLK_ROOM)) == 0) ||
 	     ((si_b->flags & (SI_FL_WANT_GET|SI_FL_WAIT_DATA)) == SI_FL_WANT_GET)))
 		appctx_wakeup(si_appctx(si_b));
 }
@@ -983,7 +984,8 @@
 		si->state = SI_ST_DIS;
 		/* fall through */
 	default:
-		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_WANT_PUT | SI_FL_NOLINGER);
+		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_NOLINGER);
+		si->flags |=  SI_FL_RX_WAIT_EP;
 		ic->flags &= ~CF_SHUTR_NOW;
 		ic->flags |= CF_SHUTR;
 		ic->rex = TICK_ETERNITY;
@@ -1416,7 +1418,7 @@
 	/* If the applet wants to write and the channel is closed, it's a
 	 * broken pipe and it must be reported.
 	 */
-	if ((si->flags & SI_FL_WANT_PUT) && (ic->flags & CF_SHUTR))
+	if (!(si->flags & SI_FL_RX_WAIT_EP) && (ic->flags & CF_SHUTR))
 		si->flags |= SI_FL_ERR;
 
 	/* update the stream-int, channels, and possibly wake the stream up */
@@ -1428,7 +1430,7 @@
 	 * we may have to wakeup the appctx immediately.
 	 */
 	if (!task_in_rq(si_task(si)) &&
-	    (((si->flags & (SI_FL_WANT_PUT|SI_FL_RXBLK_ROOM)) == SI_FL_WANT_PUT) ||
+	    (((si->flags & (SI_FL_RX_WAIT_EP|SI_FL_RXBLK_ROOM)) == 0) ||
 	     ((si->flags & (SI_FL_WANT_GET|SI_FL_WAIT_DATA)) == SI_FL_WANT_GET)))
 		appctx_wakeup(si_appctx(si));
 }
@@ -1516,7 +1518,8 @@
 		si_applet_release(si);
 		si->state = SI_ST_DIS;
 	default:
-		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_WANT_PUT | SI_FL_NOLINGER);
+		si->flags &= ~(SI_FL_RXBLK_ROOM | SI_FL_NOLINGER);
+		si->flags |= SI_FL_RX_WAIT_EP;
 		ic->flags &= ~CF_SHUTR_NOW;
 		ic->flags |= CF_SHUTR;
 		ic->rex = TICK_ETERNITY;