Documentation: Fix link to iproute2 git repository.
iproute2 git repositories were split and moved around v4.15 [1].
It is time to fix the link in OVS documentation.
1:
@@ -448,7 +448,7 @@ datapath testsuite.
an updated iproute2 utilities package. The package is available from
the Linux kernel organization open source git repositories.
- https://git.kernel.org/pub/scm/linux/kernel/git/shemminger/iproute2.git
+ https://git.kernel.org/pub/scm/network/iproute2/iproute2.git
.. _testing-static-analysis:
