Revert "UPSTREAM: mm: kmemleak: alloc gray object for reserved region with direct map"

This reverts commit bac2fa84. This
commit is not correct, and has been reverted in the upstream kernel,
so revert it on this branch as well to prepare for the correct
upstream solution. Please see [1] for more information.

[1]: https://lore.kernel.org/all/20230124230254.295589-1-isaacmanjarres@google.com/


Bug: 265065728
Change-Id: I48c51a54771b375def70d93838db54e6d804b01e
Signed-off-by: Isaac J. Manjarres <isaacmanjarres@google.com>