tests: test-admin-deploy-switch doesn't use deprecated "current" symlink
tests: test-admin-deploy-switch doesn't use deprecated "current" symlink

commit dfeb27eca55d923c57735e491e438ae54f8cc201 removed it, so change
the test to not use it.

Signed-off-by: Giuseppe Scrivano <20002b7b24c75512093a71a58285826d5c504fca@redhat.com>

sujitfulse/ostree,GNOME/ostree,GNOME/ostree,sujitfulse/ostree,GNOME/ostree,resin-io/ostree,gatispaeglis/ostree,gatispaeglis/ostree,resin-io/ostree,leandrosansilva/ostree,resin-io/ostree,resin-io/ostree,gatispaeglis/ostree,sujitfulse/ostree,GNOME/ostree,leandrosansilva/ostree,sujitfulse/ostree,gatispaeglis/ostree,leandrosansilva/ostree,sujitfulse/ostree,resin-io/ostree,GNOME/ostree,gatispaeglis/ostree,gatispaeglis/ostree,leandrosansilva/ostree,leandrosansilva/ostree