ixgbe: Fix up some ethtool results when adapter is removed

ixgbe: Fix up some ethtool results when adapter is removed

Some ethtool tests returned apparently good results when the
adapter was in a removed state. Fix that by checking for removal.
This also fixes two paths that could return uninitialized memory
in data[4].

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>