memcpy replaced with single memcpy call in ethtool.

Change-ID: I3f5bef6bcc593412c56592c6459784db41575a0a
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>