Fix Kernel.org Builders
Fix Kernel.org Builders

The Amazon prefix was accidentally dropped which resulted in a
failure to bootstrap the VM.  This string is used as a hint to
the bb-bootstrap.sh script for how to bootstrap this system.

gmelikov/zfs-buildbot,gmelikov/zfs-buildbot,zfsonlinux/zfs-buildbot,zfsonlinux/zfs-buildbot