[PATCH] staging: android: lowmemorykiller: neglect swap cached pages in other_file

Original patch https://lkml.org/lkml/2014/2/26/400
From: Vinayak Menon <vinayakm.list@gmail.com>

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.

Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com>