change database file names

change database file names

With very deeply nested devices, We can not use a single file
name to carry an entire DEVPATH. Use <subsystem>:<sysname> as
the database filename, which should also simplify the handling
of devices moving around, as these values will not change but
still be unique.

For the name stack we use the <maj>:<min> now as the filename.

> On Tue, Aug 18, 2009 at 09:59:56AM -0400, Ric Wheeler wrote:
> The first is that udev grumbles during boot about "file name too long"
> like the following:
>
> Aug 17 06:49:58 megadeth udevd-event[20447]: unable to create db file
> '/dev/.udev/db/\x2fdevices\x2fpci0000:00\x2f0000:00:04.0\x2f0000:17:00.0\x2f0000:18:0a.0\x2f0000:1f:00.0\x2fhost11\x2fport-11:0\x2fexpander-11:0\x2fport-11:0:0\x2fexpander-11:1\x2fport-11:1:0\x2fexpander-11:2\x2fport-11:2:17\x2fexpander-11:3\x2fport-11:3:1\x2fend_device-11:3:1\x2fbsg\x2fend_device-11:3:1':
> File name too long