Coding Standards: Move assignment out of condition in `phpunit/includ…

…es/speed-trap-listener.php`.

Follow-up to [45588] for `phpunit/includes/phpunit7/speed-trap-listener.php`.

See #52625.

git-svn-id: https://develop.svn.wordpress.org/trunk@50998 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/includes/speed-trap-listener.php

@@ -266,7 +266,8 @@ protected function renderBody() {
 	 * Renders slow test report footer.
 	 */
 	protected function renderFooter() {
-		if ( $hidden = $this->getHiddenCount( $this->slow ) ) {
+		$hidden = $this->getHiddenCount( $this->slow );
+		if ( $hidden ) {
 			echo sprintf( '...and there %s %s more above your threshold hidden from view', 1 === $hidden ? 'is' : 'are', $hidden );
 		}
 	}