weston-launch: Handle invalid command line options

Exit the program if an unrecognized command line option is found.

Signed-off-by; Tom Hochstein <tom.hochstein@nxp.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Reviewed-by: Yong Bakos <ybakos@humanoriented.com>
Tested-by: Yong Bakos <ybakos@humanoriented.com>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>

src/weston-launch.c

@@ -703,6 +703,8 @@ main(int argc, char *argv[])
 		case 'h':
 			help("weston-launch");
 			exit(EXIT_FAILURE);
+		default:
+			exit(EXIT_FAILURE);
 		}
 	}