Remove GetImageRoots read barrier for image relocation

Fixes CC assertion that failed if an app image was loaded when the GC
was running.

Bug: 26786304
Change-Id: I47bea7b4b947332b57be2e2db604c2c25d92b7e2
diff --git a/runtime/class_linker.cc b/runtime/class_linker.cc
index 85dfab6..894cf67 100644
--- a/runtime/class_linker.cc
+++ b/runtime/class_linker.cc
@@ -53,6 +53,7 @@
 #include "gc/heap.h"
 #include "gc/space/image_space.h"
 #include "handle_scope-inl.h"
+#include "image-inl.h"
 #include "intern_table.h"
 #include "interpreter/interpreter.h"
 #include "jit/jit.h"