linux_driver: Added bus/addr ioctl() support & corrected return values

Added the following ioctl() items:
  BLADE_GET_BUS  - Get the bus number the device is attached to
  BLADE_GET_ADDR - Get the device's address on the bus

The ioctl() return values for copy_to_user()s were directly coming from
copy_to_user. In the case that copy_to_user() fails, -EFAULT is
returned.