Don't divide layout capacity by 100

See discussion in
https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/414. Apparently the
capacity is only relative to that of other instances in the layout, it
has no absolute value of its own. We can say it corresponds to GB for
ease-of-use, but garage doesn't see it that way.

entrypoint/src/cmd/entrypoint/garage_util.go

@@ -271,7 +271,7 @@ func garageApplyLayout(
 			}
 
 			clusterLayout[id] = peerLayout{
-				Capacity: alloc.Capacity / 100,
+				Capacity: alloc.Capacity,
 				Zone:     zone,
 				Tags:     []string{},
 			}