get_hal_sysfs_path

[Richard Hughes]

Question: Does sysfs *ever* live outside of /sys?

I guess this is a question for Kay, but I think I remember some udev
configuration being removed to force sysfs to /sys IIRC.

If this is now static, we can get rid of calls to get_hal_sysfs_path
and just replace them with "/sys" - some of which are being
g_snprintf'd in the fast path or just using up space in the coldplug
code.

Richard.