MINOR: channel/applets: Stop to test CF_WRITE_ERROR flag if CF_SHUTW is enough

In applets, we stop processing when a write error (CF_WRITE_ERROR) or a shutdown
for writes (CF_SHUTW) is detected. However, any write error leads to an
immediate shutdown for writes. Thus, it is enough to only test if CF_SHUTW is
set.
diff --git a/src/debug.c b/src/debug.c
index c9b912e..05c7a5c 100644
--- a/src/debug.c
+++ b/src/debug.c
@@ -313,7 +313,7 @@
 	struct stconn *sc = appctx_sc(appctx);
 	int thr;
 
-	if (unlikely(sc_ic(sc)->flags & (CF_WRITE_ERROR|CF_SHUTW)))
+	if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
 		return 1;
 
 	if (appctx->st0)
@@ -1096,7 +1096,7 @@
 	int ret = 1;
 	int i, fd;
 
-	if (unlikely(sc_ic(sc)->flags & (CF_WRITE_ERROR|CF_SHUTW)))
+	if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
 		goto end;
 
 	chunk_reset(&trash);
@@ -1303,7 +1303,7 @@
 	const char *pfx = ctx->match;
 	int ret = 1;
 
-	if (unlikely(sc_ic(sc)->flags & (CF_WRITE_ERROR|CF_SHUTW)))
+	if (unlikely(sc_ic(sc)->flags & CF_SHUTW))
 		goto end;
 
 	if (!ctx->width) {