ret_val gets initialized to -E1000_ERR_NVM and never set differently, so
get rid of it and just return -E1000_ERR_NVM.
Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>