Add missing doc blocks to wp-admin/includes/*.

Fix some egregious uses of tabbing.
Some functions can simply return `apply_filters(...)` instead of setting a variable that is immediately returned.

See #32444.


git-svn-id: https://develop.svn.wordpress.org/trunk@32654 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/load-styles.php

@@ -81,6 +81,11 @@ function admin_url() {}
  */
 function wp_guess_url() {}
 
+/**
+ *
+ * @param string $path
+ * @return string
+ */
 function get_file($path) {
 
 	if ( function_exists('realpath') )