Web Inspector: file selector list jumps as I type or move Up/Down
https://bugs.webkit.org/show_bug.cgi?id=108933

Reviewed by Vsevolod Vlasov.

Missing return was scheduling extra updates.

* inspector/front-end/FilteredItemSelectionDialog.js:
(WebInspector.FilteredItemSelectionDialog):
(WebInspector.FilteredItemSelectionDialog.prototype._filterItems):
(WebInspector.FilteredItemSelectionDialog.prototype._onKeyDown):
(WebInspector.FilteredItemSelectionDialog.prototype._updateSelection):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@141979 268f45cc-cd09-0410-ab3c-d52691b4dbfc