Fix uname handling on some architectures
Fix uname handling on some architectures

Some arches have the uname as [65]int8, some others have it as [65]uint8.

Signed-off-by: Stéphane Graber <089afc6d81f66f1168a9849e15660feae286e024@ubuntu.com>

pcdummy/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,atxwebs/lxd,stgraber/lxd,Skarlso/lxd,erikmack/lxd,hallyn/lxd,hallyn/lxd,pcdummy/lxd,stgraber/lxd,jsavikko/lxd,lxc/lxd,Skarlso/lxd,lxc/lxd,atxwebs/lxd,mjeanson/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,atxwebs/lxd,erikmack/lxd,lxc/lxd,mjeanson/lxd,stgraber/lxd,erikmack/lxd,pcdummy/lxd,hallyn/lxd,hallyn/lxd,Skarlso/lxd,mjeanson/lxd,lxc/lxd,jsavikko/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,lxc/lxd,Skarlso/lxd,jsavikko/lxd