Properly account for text overflow in `.wp-playlist-caption` by adding `display: block`.

Props celloexpressions.
See #27923.



git-svn-id: https://develop.svn.wordpress.org/trunk@28172 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/js/mediaelement/wp-mediaelement.css

@@ -98,6 +98,7 @@
 }
 
 .wp-playlist-caption {
+	display: block;
 	max-width: 88%;
 	overflow: hidden;
 	text-overflow: ellipsis;