zram swap: LMK and memcontrol update from Samsung SGS 4 update 2 source drop

Signed-off-by: Paul Reioux <reioux@gmail.com>
lowmemorykiller: fix GCC-4.7 compiler warning

Signed-off-by: Paul Reioux <reioux@gmail.com>
decompressor: Add LZ4 decompressor module