e1000e: Fix error handling in e1000_set_d0_lplu_state_82571

e1000e: Fix error handling in e1000_set_d0_lplu_state_82571

There is one e1e_wphy() call in e1000_set_d0_lplu_state_82571
that we have caught its return value but lack further handling.
Check and terminate the execution flow just like other e1e_wphy()
in this function.

Fixes: 3f32e81cc0ea ("[E1000E]: New pci-express e1000 driver (currently for ICH9 devices only)")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>