e1000e: release hw semaphore after successfully writing EEPROM

Since e1000e has been existance in linux-2.6, we've
never released the hardware semaphore after a successful
write to the SPI EEPROM. I guess we don't write to
SPI EEPROM much -- but those few of us that do appreciate
it when we can later read from the EEPROM without having
to reboot.

Found-by: Nick Van Fossen <[e-mail]>
Signed-off-by: Arthur Jones <[e-mail]>
Reviewed-by: Auke Kok <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/e1000e/lib.c

···
 	}
 
 	msleep(10);
+	nvm->ops.release_nvm(hw);
 	return 0;
 }