ixgbe: remove unnecessary re-init of adapter on Rx-csum change

There is no need to reset the adapter when changing the Rx checksum
settings. Since the only change is a software flag we can disable it
without needing to reset the entire adapter.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>