[CFT] Patch to bsdinstall to support root-on-ZFS and GELI

[Johan Broman]

Hi!

Just tested the root-on-ZFS install option using FreeBSD 10 beta 1. I 
have 4 SATA drives in my server. I select all four of them in a RAIDZ1 
setup. I hit enter to continue the installation and the zpool is 
created, but I'm then returned to the zpool selection screen again. It 
turned out that two of the drives had previously been used in a (Linux) 
software mirror setup and because of this they got activated in 
/dev/raid/r0. Because of this I ended up in an endless bsdinstall loop.

Removing the raid device using the graid command resolved the situation.

Now maybe this is working as designed, but there was no warning/alert to 
the fact that the devices couldn't be used. Perhaps a warning should be 
rasied in this situation?

Thanks for all the great work on the new installer, really looking 
forward to FreeBSD 10!

Cheers
Johan