Added two tests which checks the following fixed issues:

    1) Bug when not possible add new virtual interface via:

        $ ip link add dev XXX type

       It was fixed a few releases ago.

    2) Crash on older kernels when VF rate info does not exist:

        $ ip link show

       Used dump file from William Dauchy <william@gandi.net>:
           testsuite/tests/ip/link/dev_wo_vf_rate.nl

       So 'ip link show' replaced by 'ip -d monitor file ...' which does
       the same thing.

Also added new func in testsuite/lib/generic.sh to gen new random dev name.

Added 'clean' dependency on running all tests.
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>