fix: vcsim -load Datastore summary.url property

PR #3705 refactored Datastore access, part of which uses the
Datastore summary.url property instead of info.url

Also fix the Datastore urls for local paths,
such as govc object.save of a vcsim instance

Signed-off-by: Doug MacEachern <[email protected]>

Author: dougm

govc/test/vcsim.bats

@@ -564,6 +564,10 @@ EOF
 
   run govc host.portgroup.add -host DC0_H0 -vswitch vSwitch0 bridge
   assert_success # issue #2016
+
+  # make sure we can write the save/load-ed Datastore
+  run govc import.ova "$GOVC_IMAGES/$TTYLINUX_NAME.ova"
+  assert_success
 }
 
 @test "vcsim trace file" {

simulator/datastore.go

@@ -49,8 +49,19 @@ func (ds *Datastore) model(m *Model) error {
 			return err
 		}
 
+		info.Url = dir
+	} else {
+		// rewrite local path from a saved vcsim instance
+		dir, err := m.createTempDir(path.Base(u.Path))
+		if err != nil {
+			return err
+		}
+
 		info.Url = dir
 	}
+
+	ds.Summary.Url = info.Url
+
 	return nil
 }