Accessing GEOM disks from libdisk

[Sean Bruno]

I've been trying to access disk information from the libdisk routines 
and keep hitting a core dump on Open_Disk().  It's probably operator 
head-space on my part, but I can't quite see how to do it properly. 

eg.  GEOM disk is /dev/concat/disk1

Running the tst01 utility from src/lib/libdisk core dumps when I pass 
/dev/concat/disk1, concat/disk1 or just disk1 in as the disk argument. 

Running the tst01 utility against the non GEOM disks works just fine, 
eg.  /dev/ad4:  tst01 ad4

Can libdisk access GEOM devices?

Sean