Pull driver core fix from Greg KH:
"Here is one fix for the hotplug memory path that resolves a regression
when removing memory that showed up in 3.12-rc1"
* tag 'driver-core-3.12-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
driver core: Release device_hotplug_lock when store_mem_state returns EINVAL