be2net: init (vf)_if_handle/vf_pmac_id to handle failure scenarios

Initialize if_handle, vf_if_handle and vf_pmac_id with "-1" so that in
failure cases when be_clear() is called, we can skip over
if_destroy/pmac_del cmds if they have not been created.

Signed-off-by: Sathya Perla <sathya.perla@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>