fcoe: correct checking for bonding

Check for bonding master and refuse to use that.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Robert Love <robert.w.love@intel.com>
Acked-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>