Fix bad merge

Test: Boot device, hope for the best
Change-Id: I0231874a5f4d7cc8b49cc6f978c17c1af6fa93be
Fixes: 34227241
diff --git a/services/core/java/com/android/server/wm/AppWindowContainerController.java b/services/core/java/com/android/server/wm/AppWindowContainerController.java
index 1eb74fa4..9b2d3c6b 100644
--- a/services/core/java/com/android/server/wm/AppWindowContainerController.java
+++ b/services/core/java/com/android/server/wm/AppWindowContainerController.java
@@ -92,6 +92,9 @@
             if (DEBUG_STARTING_WINDOW) Slog.v(TAG_WM, "Remove starting " + mContainer
                     + ": startingWindow=" + mContainer.startingWindow
                     + " startingView=" + mContainer.startingSurface);
+            if (mContainer == null) {
+                return;
+            }
             if (mContainer.startingWindow != null) {
                 surface = mContainer.startingSurface;
                 data = mContainer.startingData;