[AX25]: Switch to using ctl_paths.

This one is almost the same as the hunks in the
first patch, but ax25 tables are created dynamically.

So this patch differs a bit to handle this case.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>