modules/smartos_vmadm : add setmem(uuid, memory) function

This function identifies the VM type (OS -> realtime update, or KVM ->
reboot), and sets the correct amount of memory. Warning : there are no
checks against the CN : you could accidentally permit the VM to eat all
the RAM available on the baremetal...
modules/smartos_vmadm : fix a missing variable reference
Merge pull request #5325 from virtua-network/smartos_vmadm

modules/smartos_vmadm : add setmem(uuid, memory) function