Make class roots an image root

Change-Id: I1f1513bf34caa736c0dd7518a92f493b4573d776
diff --git a/src/runtime.h b/src/runtime.h
index bd2c7a2..8252a60 100644
--- a/src/runtime.h
+++ b/src/runtime.h
@@ -191,7 +191,7 @@
   // The host prefix is used during cross compilation. It is removed
   // from the start of host paths such as:
   //    $ANDROID_PRODUCT_OUT/system/framework/core.oat
-  // to produce target paths such as 
+  // to produce target paths such as
   //    /system/framework/core.oat
   // Similarly it is prepended to target paths to arrive back at a
   // host past. In both cases this is necessary because image and oat