fetch2: Correct a few calls to latest_revision()

In 6a48474de9505a3700863f31839a7c53c5e18a8d the url parameter to a
number of functions was removed. However, not all calls to
latest_revision() were fixed...

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>