The way devices are mapped is a bit more complex than before.
This implements the method from new_decode_dev in:
https://github.com/mirrors/linux-2.6/blob/master/include/linux/kdev_t.h
Which is what is needed on kernels > 2.6
Upstream-commit: 572b1fd9be69c20a98d885e18b327031ef4f4b51
Component: engine