Media: In `WP_Image_Editor::make_image()`, close previously opened output buffer if the file could not be created.

Props dhanendran, gnif.
Fixes #43255.

git-svn-id: https://develop.svn.wordpress.org/trunk@42695 602fd350-edb4-49c9-b593-d223f7449a82

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

@@ -409,6 +409,9 @@ abstract class WP_Image_Editor {
 			$fp = fopen( $filename, 'w' );
 
 			if ( ! $fp ) {
+				if ( $stream ) {
+					ob_end_clean();
+				}
 				return false;
 			}