Merge tag 'driver-core-3.15-rc6' of git://

Pull driver core fixes from Greg KH:
 "Here are two driver core (well, sysfs) fixes for 3.15-rc6 that resolve
  some reported issues and a regression from 3.13"

* tag 'driver-core-3.15-rc6' of git://
  sysfs: make sure read buffer is zeroed
  kernfs, sysfs, cgroup: restrict extra perm check on open to sysfs