w1: use put_device() if device_register() fail

If device_register() returned an error! Always use put_device()
to give up the reference initialized in device_register().

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>