Revert "mm/memblock: fix a race between search and remove"

This reverts commit eb292c2a.

The reverted patch is part of the unused no-map-fixup feature
which is being removed.

Change-Id: I991db27193be58541348535f40fe87c7a0242148
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>