Fix the return docs for `WP_Embed->maybe_make_link()`.

See #30224.


git-svn-id: https://develop.svn.wordpress.org/trunk@30178 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-embed.php

@@ -334,7 +334,7 @@ class WP_Embed {
 	 * Conditionally makes a hyperlink based on an internal class variable.
 	 *
 	 * @param string $url URL to potentially be linked.
-	 * @return string Linked URL or the original URL.
+	 * @return string|bool Linked URL or the original URL. False if 'return_false_on_fail' is true.
 	 */
 	public function maybe_make_link( $url ) {
 		if ( $this->return_false_on_fail ) {