aries | p1: staging: zram: Rename module parameter

zram accepts number of devices to be created
as a module parameter. This was renamed from
num_devices to zram_num_devices (without updating
the documentation!) since num_devices was declared
as a non-static global variable, polluting the global
namespace. Now, we declare it as a static variable
and revert back the name change.

The documentation (zram.txt) already mentions
num_devices as the module parameter name.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Humberto Borba <humberos@gmail.com>

Change-Id: I96a390ce1884613952826b305415ddaa6db93a68
Merge "aries | p1: staging: zram: Rename module parameter" into android-4.4