In `WP_Image_Editor::get_output_format()`, `$file_mime` and `$file_ext` are set twice before they are used.

See #27882.

Built from https://develop.svn.wordpress.org/trunk@28320


git-svn-id: http://core.svn.wordpress.org/trunk@28148 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/class-wp-image-editor.php

@@ -270,8 +270,7 @@ abstract class WP_Image_Editor {
 	 * @return array { filename|null, extension, mime-type }
 	 */
 	protected function get_output_format( $filename = null, $mime_type = null ) {
-		$new_ext = $file_ext = null;
-		$file_mime = null;
+		$new_ext = null;
 
 		// By default, assume specified type takes priority
 		if ( $mime_type ) {