Coding Standards: Use strict comparison in `wp_check_post_hierarchy_f…

…or_loops()`.

Follow-up to [10129], [15806].

Props aristath, poena, afercia, SergeyBiryukov.
See #62279.

git-svn-id: https://develop.svn.wordpress.org/trunk@59597 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/post.php

@@ -7934,7 +7934,7 @@ function wp_check_post_hierarchy_for_loops( $post_parent, $post_id ) {
 	}
 
 	// Can't be its own parent.
-	if ( $post_parent == $post_id ) {
+	if ( $post_parent === $post_id ) {
 		return 0;
 	}