Fix PHPDoc

That apparently went lost when changing the signature.

lib/public/appframework/http/icallbackresponse.php

@@ -21,7 +21,7 @@ interface ICallbackResponse {
 	/**
 	 * Outputs the content that should be printed
 	 *
-	 * @param IOutput a small wrapper that handles output
+	 * @param IOutput $output a small wrapper that handles output
 	 */
 	function callback(IOutput $output);
 

lib/public/appframework/http/streamresponse.php

@@ -32,7 +32,7 @@ class StreamResponse extends Response implements ICallbackResponse {
 	/**
 	 * Streams the file using readfile
 	 *
-	 * @param IOutput a small wrapper that handles output
+	 * @param IOutput $output a small wrapper that handles output
 	 */
 	public function callback (IOutput $output) {
 		// handle caching