linux/drivers/base/core.c: device_get_devnode() defines a translation of
'!' in sysfs nodes to '/' in /dev nodes. The same translation has to be
done to properly support device nodes with slash (e. g. device nodes of
cciss driver and several other drivers).
Introduce new helper sysfs_devname_to_devno() and use it where
appropriate.
Fixes for example lsblk -f on devices using cciss driver.