Fix potential dex index overflow in dx

Revert change to dex rotation algorithm made as part of commit:
845d9d0eed0f6556e11ee7f7204fda9c8dd41154

Bug: https://code.google.com/p/android/issues/detail?id=161887
Change-Id: I255aa52b74c921a78e77671ae6187157fef011e1
Signed-off-by: Peter Jensen <jensenp@google.com>
2 files changed