staging: android: lowmemorykiller: neglect swap cached pages in other_file

staging: android: lowmemorykiller: neglect swap cached pages in other_file

With ZRAM enabled it is observed that lowmemory killer
doesn't trigger properly. swap cached pages are
accounted in NR_FILE, and lowmemorykiller considers
this as reclaimable and adds to other_file. But these
pages can't be reclaimed unless lowmemorykiller triggers.
So subtract swap pages from other_file.

Bug 200031574

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 058dbde928597e7a8bd04e28e77e5cfc4270591d)
Change-Id: Ic268437b65e89496244289adffa8bac80df88c28
Signed-off-by: Sri Krishna chowdary <schowdary@nvidia.com>
Reviewed-on: http://git-master/r/497231
(cherry picked from commit 1eec4665e479908911713705e384da8a6d5b66b1)
(cherry picked from commit 29ed5bc606765584b30fa7d025c0d49a02a6e7e4)
Reviewed-on: http://git-master/r/539291
Reviewed-by: Dhiren Parmar <dparmar@nvidia.com>