Coding Standards: Rename $thisEnclosure variable in wp_xmlrpc_server methods.

This resolves a WPCS warning:
{{{
Variable "$thisEnclosure" is not in valid snake_case format, try "$this_enclosure"
}}}

Follow-up to [16824], [19848].

See #62279.

git-svn-id: https://develop.svn.wordpress.org/trunk@59680 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/class-wp-xmlrpc-server.php

@@ -5623,8 +5623,8 @@ public function mw_newPost( $args ) {
 		}
 
 		// Handle enclosures.
-		$thisEnclosure = isset( $content_struct['enclosure'] ) ? $content_struct['enclosure'] : null;
-		$this->add_enclosure_if_new( $post_id, $thisEnclosure );
+		$enclosure = isset( $content_struct['enclosure'] ) ? $content_struct['enclosure'] : null;
+		$this->add_enclosure_if_new( $post_id, $enclosure );
 
 		$this->attach_uploads( $post_id, $post_content );
 
@@ -6019,8 +6019,8 @@ public function mw_editPost( $args ) {
 		}
 
 		// Handle enclosures.
-		$thisEnclosure = isset( $content_struct['enclosure'] ) ? $content_struct['enclosure'] : null;
-		$this->add_enclosure_if_new( $post_id, $thisEnclosure );
+		$enclosure = isset( $content_struct['enclosure'] ) ? $content_struct['enclosure'] : null;
+		$this->add_enclosure_if_new( $post_id, $enclosure );
 
 		$this->attach_uploads( $ID, $post_content );