Remove the assumption that driver_register() returns the number of devices
bound to the driver. In fact, it returns zero for success or a negative
error value.
Nobody uses the return value of of_register_driver() anyway.
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Paul Mackerras <paulus@samba.org>