get_newest_label() will always return a refcount, on the profile it
returns. However there are cases where we only need the refcount
if the label is stale and get_newest_label() will return a different
label.
Optimize this by making the get/put happen conditionally, by keeping
a flag indicating if the get was performed and a put is needed.
Signed-off-by: John Johansen <john.johansen@canonical.com>