Pull driver core fixes from Greg KH:
"Here are some kernfs fixes for 3.15-rc3 that resolve some reported
problems. Nothing huge, but all needed"
* tag 'driver-core-3.15-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
s390/ccwgroup: Fix memory corruption
kernfs: add back missing error check in kernfs_fop_mmap()
kernfs: fix a subdir count leak