MINOR: cli: give the show_fd helpers the ability to report a suspicious entry

Now the show_fd helpers at the transport and mux levels return an integer
which indicates whether or not the inspected entry looks suspicious. When
an entry is reported as suspicious, "show fd" will suffix it with an
exclamation mark ('!') in the dump, that is supposed to help detecting
them.

For now, helpers were adjusted to adapt to the new API but none of them
reports any suspicious entry yet.

(cherry picked from commit 8050efeacb554f798a49db5ef213c8f673e5596e)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/src/ssl_sock.c b/src/ssl_sock.c
index 4b4ab21..8f3159f 100644
--- a/src/ssl_sock.c
+++ b/src/ssl_sock.c
@@ -6249,12 +6249,12 @@
 /* "show fd" helper to dump ssl internals. Warning: the output buffer is often
  * the common trash!
  */
-static void ssl_sock_show_fd(struct buffer *buf, const struct connection *conn, const void *ctx)
+static int ssl_sock_show_fd(struct buffer *buf, const struct connection *conn, const void *ctx)
 {
 	const struct ssl_sock_ctx *sctx = ctx;
 
 	if (!sctx)
-		return;
+		return 0;
 
 	if (sctx->conn != conn)
 		chunk_appendf(&trash, " xctx.conn=%p(BOGUS!)", sctx->conn);
@@ -6278,6 +6278,7 @@
 	}
 	chunk_appendf(&trash, " .sent_early=%d", sctx->sent_early_data);
 	chunk_appendf(&trash, " .early_in=%d", (int)sctx->early_buf.data);
+	return 0;
 }
 
 /* This function is used with TLS ticket keys management. It permits to browse