zram compression algorithm should be configurable

zram

 # The factor is swap/RAM ratio in percents
 FACTOR=100
+
+# The compressor is algorithm to use for compression
+COMPRESSOR=lzo-rle

zramstart

 #!/bin/sh
 
 FACTOR=66
+COMPRESSOR=lzo-rle
 [ -f /etc/zram ] && source /etc/zram || true
 factor=$FACTOR # percentage
+compressor=$COMPRESSOR # compressor
 
 memtotal=$(grep MemTotal /proc/meminfo | awk ' { print $2 } ')
 mem_used=$(($memtotal*$factor/100*1024))
 
 modprobe -q zram
-grep -q lzo-rle /sys/block/zram0/comp_algorithm && echo lzo-rle > /sys/block/zram0/comp_algorithm
+grep -q $compressor /sys/block/zram0/comp_algorithm && echo $compressor > /sys/block/zram0/comp_algorithm
 echo $mem_used > /sys/block/zram0/disksize
 mkswap /dev/zram0
 swapon -p 100 /dev/zram0