Bail if activity was destroyed.

Bug: 24172045
Change-Id: I723951b3478459fc70e29d25386f8d7197964e3d
diff --git a/src/com/android/settings/deviceinfo/StorageWizardFormatProgress.java b/src/com/android/settings/deviceinfo/StorageWizardFormatProgress.java
index 6f89ff5..6f73ecd 100644
--- a/src/com/android/settings/deviceinfo/StorageWizardFormatProgress.java
+++ b/src/com/android/settings/deviceinfo/StorageWizardFormatProgress.java
@@ -137,6 +137,10 @@
         @Override
         protected void onPostExecute(Exception e) {
             final StorageWizardFormatProgress activity = mActivity;
+            if (activity.isDestroyed()) {
+                return;
+            }
+
             if (e != null) {
                 Log.e(TAG, "Failed to partition", e);
                 Toast.makeText(activity, e.getMessage(), Toast.LENGTH_LONG).show();