zram: simplify and optimize dev_to_zram()

Simplify and optimize dev_to_zram() without walking the zram_devices
array.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 80de574dca050b734d8413a98a983fba3d06240b)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
1 file changed