Docs: Fix incorrect @return tag in wp_check_filetype() tests.

`@return[]` is not a valid tag. Fixed now, though without further specification.

Reference: [https://developer.wordpress.org/coding-standards/inline-documentation-standards/php/#phpdoc-tags PHP Documentation Standards: PHPDoc Tags].

Follow-up to [55456].

Props jrf.
See #59651.

git-svn-id: https://develop.svn.wordpress.org/trunk@57101 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/functions/wpCheckFiletype.php

@@ -28,7 +28,7 @@ class Tests_Functions_WpCheckFiletype extends WP_UnitTestCase {
 	/**
 	 * Data provider.
 	 *
-	 * @return[]
+	 * @return array[]
 	 */
 	public function data_wp_check_filetype() {
 		return array(
@@ -105,7 +105,6 @@ class Tests_Functions_WpCheckFiletype extends WP_UnitTestCase {
 					'type' => false,
 				),
 			),
-
 		);
 	}
 }