Revert "lowmemorykiller: Don't count reserve page twice"

This reverts commit d73f05ceab2717c23f00bfeffa31a7dedd15569a.

The patch is causing device crash while running
kernel tests on mainline. The change was to
make LMK less aggressive.

Change-Id: I272bf5ccd54a29de1c770d69af7fea2963f46333
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>