device_cgroup.h: delete needless include <linux/module.h>

There is nothing modular in this file, and no reason to drag
in all the extra headers that module.h brings with it, since
it just slows down compiles.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

include/linux/device_cgroup.h

-#include <linux/module.h>
 #include <linux/fs.h>
 
 #ifdef CONFIG_CGROUP_DEVICE