Coding Standards: Remove redundant conditional in WP_Customize_Manager.

This check would always be true, as `::handle_changeset_trash_request()` returns early a few lines above  if `$changeset_post_id` is false.

Follow-up to [41667], [48211].

Props justlevine.
See #63268.

git-svn-id: https://develop.svn.wordpress.org/trunk@60414 602fd350-edb4-49c9-b593-d223f7449a82

Author: SergeyBiryukov

src/wp-includes/class-wp-customize-manager.php

@@ -3165,27 +3165,25 @@ public function handle_changeset_trash_request() {
 			return;
 		}
 
-		if ( $changeset_post_id ) {
-			if ( ! current_user_can( get_post_type_object( 'customize_changeset' )->cap->delete_post, $changeset_post_id ) ) {
-				wp_send_json_error(
-					array(
-						'code'    => 'changeset_trash_unauthorized',
-						'message' => __( 'Unable to trash changes.' ),
-					)
-				);
-			}
+		if ( ! current_user_can( get_post_type_object( 'customize_changeset' )->cap->delete_post, $changeset_post_id ) ) {
+			wp_send_json_error(
+				array(
+					'code'    => 'changeset_trash_unauthorized',
+					'message' => __( 'Unable to trash changes.' ),
+				)
+			);
+		}
 
-			$lock_user = (int) wp_check_post_lock( $changeset_post_id );
+		$lock_user = (int) wp_check_post_lock( $changeset_post_id );
 
-			if ( $lock_user && get_current_user_id() !== $lock_user ) {
-				wp_send_json_error(
-					array(
-						'code'     => 'changeset_locked',
-						'message'  => __( 'Changeset is being edited by other user.' ),
-						'lockUser' => $this->get_lock_user_data( $lock_user ),
-					)
-				);
-			}
+		if ( $lock_user && get_current_user_id() !== $lock_user ) {
+			wp_send_json_error(
+				array(
+					'code'     => 'changeset_locked',
+					'message'  => __( 'Changeset is being edited by other user.' ),
+					'lockUser' => $this->get_lock_user_data( $lock_user ),
+				)
+			);
 		}
 
 		if ( 'trash' === get_post_status( $changeset_post_id ) ) {