Revert "UPSTREAM: mm: use alloc_flags to record if kswapd can wake"

This reverts commit 112ced56.

Reason for revert: revert customized code
Bug: 140544941
Test: boot
Signed-off-by: Minchan Kim <minchan@google.com>
Signed-off-by: Martin Liu <liumartin@google.com>
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I400cabb69dc9e24ea5d84f677315dbb3bfd34e45