Twenty Seventeen: Fix smooth scrolling skip link

The link was scrolling too far. The main problem was that the `menuTop` variable lost it's initial definition of `0`, so all future subtractions were failing.

Props tywayne.

Fixes #38448.


git-svn-id: https://develop.svn.wordpress.org/trunk@38886 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-content/themes/twentyseventeen/assets/js/global.js

@@ -23,7 +23,7 @@
 			idealNavHeight,
 			navIsNotTooTall,
 			headerOffset,
-			menuTop,
+			menuTop = 0,
 			resizeTimer;
 
 	/**
@@ -149,7 +149,7 @@
 			 * 'Scroll Down' arrow in menu area
 			 */
 			if ( $( 'body' ).hasClass( 'admin-bar' ) ) {
-				menuTop = -32;
+				menuTop -= 32;
 			}
 			if ( $( 'body' ).hasClass( 'blog' ) ) {
 				menuTop -= 30; // The div for latest posts has no space above content, add some to account for this