show filter message only when filter not provided

Signed-off-by: Ola Næss Kaldestad <mail@okal.no>

cmd/tailscale/cli/exitnode.go

@@ -137,7 +137,9 @@ func runExitNodeList(ctx context.Context, args []string) error {
 	}
 	fmt.Fprintln(w)
 	fmt.Fprintln(w)
-	fmt.Fprintln(w, "# To view the complete list of exit nodes for a country, use `tailscale exit-node list --filter=` followed by the country name.")
+	if exitNodeArgs.filter == "" {
+		fmt.Fprintln(w, "# To view the complete list of exit nodes for a country, use `tailscale exit-node list --filter=` followed by the country name.")
+	}
 	fmt.Fprintln(w, "# To use an exit node, use `tailscale set --exit-node=` followed by the hostname or IP.")
 	if hasAnyExitNodeSuggestions(peers) {
 		fmt.Fprintln(w, "# To have Tailscale suggest an exit node, use `tailscale exit-node suggest`.")