virsh: fix uninitialized variable in cmdSnapshotEdit
virsh: fix uninitialized variable in cmdSnapshotEdit

https://bugzilla.redhat.com/show_bug.cgi?id=877303

If the domain can't be looked up, name is used unitialized after the
cleanup label.

Found by coverity.
(cherry picked from commit 689b64d666bc268d55395a92a2b9d6cd51b3ad70)

mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2,mithleshvrts/libvirt-0.10.2