Merge pull request #2227 from bansiesta/fix_mixer_cli

systemcmds: the mixer shuts up now

src/systemcmds/mixer/mixer.cpp

@@ -80,8 +80,10 @@ mixer_main(int argc, char *argv[])
 			warnx("failed to load mixer");
 			return 1;
 		}
+	} else {
+		usage("Unknown command");
+		return 1;
 	}
-	usage("Unknown command");
 	return 0;
 }