Show lint errors when there are lint problems (#9661)

A summary saying there were lint errors isn't too helpful
when you want to fix the lint errors, so this changes
the output so that the lint failures are shown.

composer.json

@@ -21,6 +21,6 @@
 	},
 	"scripts": {
 		"format": "phpcbf --standard=phpcs.xml.dist --report-summary --report-source",
-		"lint": "phpcs --standard=phpcs.xml.dist --report-summary --report-source"
+		"lint": "phpcs --standard=phpcs.xml.dist"
 	}
 }