Revert "ANDROID: dm-bow: Protect Ranges fetched and erased from the RB tree"

This reverts commit b94d6fe4.

Reason for revert: Needs rework - causes unforeseen deadlock.

Bug: 227141277
Change-Id: Ie883d7055dbcac70dd8bfd0d4ab45c274cd127c8
Signed-off-by: Lee Jones <joneslee@google.com>