Fixing null check when calling mutateOnMainThread

Bug: 25269169
Change-Id: I74f7fb833a374f59a16487099f1bf72b086e88ee
diff --git a/src/com/android/launcher3/WidgetPreviewLoader.java b/src/com/android/launcher3/WidgetPreviewLoader.java
index 603b072..10c1053 100644
--- a/src/com/android/launcher3/WidgetPreviewLoader.java
+++ b/src/com/android/launcher3/WidgetPreviewLoader.java
@@ -428,8 +428,9 @@
             float iconScale = Math.min((float) smallestSide / (appIconSize + 2 * minOffset), scale);
 
             try {
-                Drawable icon = mutateOnMainThread(mManager.loadIcon(info, mIconCache));
+                Drawable icon = mManager.loadIcon(info, mIconCache);
                 if (icon != null) {
+                    icon = mutateOnMainThread(icon);
                     int hoffset = (int) ((tileW - appIconSize * iconScale) / 2) + x;
                     int yoffset = (int) ((tileH - appIconSize * iconScale) / 2);
                     icon.setBounds(hoffset, yoffset,