Fix applying of focus styles to .vectorMenu handle

The .vectorMenuFocus class was being added on the wrong element, so
the styles for it never kicked in. I think this has been broken since
4fabc910d2e1bb4581ac7a80f019bd22758d089b (August 2013), which is
understandable since the style change is near impossible to notice
(the little triangle arrow turns a slightly lighter shade of grey).

Change-Id: I0f7881afde9e01061aacf009033255774d0acd8d

vector.js

@@ -41,10 +41,10 @@ jQuery( function ( $ ) {
 			} )
 			// When the heading has focus, also set a class that will change the arrow icon
 			.focus( function () {
-				$el.find( '> span' ).addClass( 'vectorMenuFocus' );
+				$el.addClass( 'vectorMenuFocus' );
 			} )
 			.blur( function () {
-				$el.find( '> span' ).removeClass( 'vectorMenuFocus' );
+				$el.removeClass( 'vectorMenuFocus' );
 			} );
 	} );