Meta: Don't pass an empty `$meta_key` to `get_metadata()`.

This doesn't break anything, but also isn't necessary.

Props sc0ttkclark.
See #35658.

Built from https://develop.svn.wordpress.org/trunk@37996


git-svn-id: http://core.svn.wordpress.org/trunk@37937 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/meta.php

@@ -1239,7 +1239,7 @@ function get_registered_metadata( $object_type, $object_subtype, $object_id, $me
 		return $data;
 	}
 
-	$data = get_metadata( $object_type, $object_id, $meta_key );
+	$data = get_metadata( $object_type, $object_id );
 
 	$meta_keys = get_registered_meta_keys( $object_type, $object_subtype );
 	$registered_data = array();

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.6-beta2-37995';
+$wp_version = '4.6-beta2-37996';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.