tests: check that `route()` accepts `oif` as list
tests: check that `route()` accepts `oif` as list

Some people directly pass the result of `link_lookup()` to the `route()`. Since
it is works (occasionally, though), one should keep it compatible now.
simudream/pyroute2,drzaeus77/pyroute2,mtiny/pyroute2,vodik/pyroute2,roolebo/pyroute2,mtiny/pyroute2,simudream/pyroute2,vodik/pyroute2,tomislacker/python-iproute2,roolebo/pyroute2,tomislacker/python-iproute2,drzaeus77/pyroute2