image: fix size (Quantity) string format
image: fix size (Quantity) string format

Fix string formatting of size arg, to resolve:
"Sprintf format %s has arg size of wrong type .../resource.Quantity"

Change-Id: I5061a98359abfaf4204e53e636a01a3dcdca8efa
Signed-off-by: Daniel Erez <2f9e6efa5394039257912622b475da08d58ee4c7@redhat.com>

kubevirt/containerized-data-importer,kubevirt/containerized-data-importer,kubevirt/containerized-data-importer