Fix NPE in case where workspace is null because Launcher has been destroyed 

Bug: 11765964
Change-Id: Iacd4db712c09940c05ccd2a64b25e376b63c6aee
diff --git a/src/com/android/launcher3/Launcher.java b/src/com/android/launcher3/Launcher.java
index 7d84a3c..ce6b20e 100644
--- a/src/com/android/launcher3/Launcher.java
+++ b/src/com/android/launcher3/Launcher.java
@@ -2663,7 +2663,7 @@
     }
 
     public void closeFolder() {
-        Folder folder = mWorkspace.getOpenFolder();
+        Folder folder = mWorkspace != null ? mWorkspace.getOpenFolder() : null;
         if (folder != null) {
             if (folder.isEditingName()) {
                 folder.dismissEditingName();