backend/remote: Fix broken state lock retry

When using the -lock-timeout option with the remote backend configured
in local operations mode, Terraform would fail to retry acquiring the
lock. This was caused by the lock error message having a missing Info
field, which the state manager requires to be present in order to
attempt retries.

backend/remote/backend_state.go

@@ -117,6 +117,7 @@ func (r *remoteClient) Lock(info *statemgr.LockInfo) (string, error) {
 	})
 	if err != nil {
 		if err == tfe.ErrWorkspaceLocked {
+			lockErr.Info = info
 			err = fmt.Errorf("%s (lock ID: \"%s/%s\")", err, r.organization, r.workspace.Name)
 		}
 		lockErr.Err = err