Coding Standards: Remove a one-time variable in WP_MS_Sites_List_Table::prepare_items().

This allows the `$wpdb::prepare()` call to be picked up correctly by PHPCS.

Follow-up to [28712], [55656].

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

git-svn-id: https://develop.svn.wordpress.org/trunk@60069 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-admin/includes/class-wp-ms-sites-list-table.php

@@ -115,13 +115,13 @@ public function prepare_items() {
 			|| preg_match( '/^[0-9]{1,3}\.$/', $s )
 		) {
 			// IPv4 address.
-			$sql = $wpdb->prepare(
-				"SELECT blog_id FROM {$wpdb->registration_log} WHERE {$wpdb->registration_log}.IP LIKE %s",
-				$wpdb->esc_like( $s ) . ( ! empty( $wild ) ? '%' : '' )
+			$reg_blog_ids = $wpdb->get_col(
+				$wpdb->prepare(
+					"SELECT blog_id FROM {$wpdb->registration_log} WHERE {$wpdb->registration_log}.IP LIKE %s",
+					$wpdb->esc_like( $s ) . ( ! empty( $wild ) ? '%' : '' )
+				)
 			);
 
-			$reg_blog_ids = $wpdb->get_col( $sql );
-
 			if ( $reg_blog_ids ) {
 				$args['site__in'] = $reg_blog_ids;
 			}