build: Fix path to /git/calamari-clients

This was hardcoded for the old repo name.  It's still
undesirable for the path here to be hardcoded at all,
but at least this will work with a default-named
checkout.

Signed-off-by: John Spray <john.spray@redhat.com>
Merge pull request #34 from ceph/wip-build

build: Fix path to /git/calamari-clients