staging: zram: make global var "devices" use unique name

The global variable "devices" is too general to be global.
This patch switches the name to be "zram_devices".

Signed-off-by: Noah Watkins <noahwatkins@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --cc drivers/staging/zram/zram_drv.c
Simple merge

diff --cc drivers/staging/zram/zram_drv.h
Simple merge

diff --cc drivers/staging/zram/zram_sysfs.c
Simple merge