fix path to icecream symlinks

6a3dff2135e2ca68efd8925b197b39b6f99d4872 was incorrect, the directory
name is icecc, not icecream. This means 'build --icecream' doesn't
work on openSUSE12.3 :(.
fix swap image usage for uml, fix naming for root dev for uml
Merge pull request #55 from llunak/master

Fix path to icecream symlinks
Restrict initvm usage to x86_64

This binary is only running on x86_64 hosts,
it does not make sense on armv7l hosts with kvm.