intel: remove checker warning

The sparse checker (C=2) found an assignment where we were mixing
types when trying to convert from data read directly from the
device NVM, to an array in CPU order in-memory, which
unfortunately the driver tries to do in-place.

This is easily solved by using the swap operation instead of an
assignment, and is already proven in other Intel drivers to be
functionally correct and the same code, just without a sparse
warning.

The change is the same in all three drivers.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Dave Switzer <david.switzer@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/e1000/e1000_ethtool.c

@@ -513,7 +513,7 @@ static int e1000_set_eeprom(struct net_device *netdev,
 	memcpy(ptr, bytes, eeprom->len);
 
 	for (i = 0; i < last_word - first_word + 1; i++)
-		eeprom_buff[i] = cpu_to_le16(eeprom_buff[i]);
+		cpu_to_le16s(&eeprom_buff[i]);
 
 	ret_val = e1000_write_eeprom(hw, first_word,
 				     last_word - first_word + 1, eeprom_buff);

drivers/net/ethernet/intel/igb/igb_ethtool.c

@@ -831,7 +831,7 @@ static int igb_set_eeprom(struct net_device *netdev,
 	memcpy(ptr, bytes, eeprom->len);
 
 	for (i = 0; i < last_word - first_word + 1; i++)
-		eeprom_buff[i] = cpu_to_le16(eeprom_buff[i]);
+		cpu_to_le16s(&eeprom_buff[i]);
 
 	ret_val = hw->nvm.ops.write(hw, first_word,
 				    last_word - first_word + 1, eeprom_buff);

drivers/net/ethernet/intel/igc/igc_ethtool.c

@@ -554,7 +554,7 @@ static int igc_ethtool_set_eeprom(struct net_device *netdev,
 	memcpy(ptr, bytes, eeprom->len);
 
 	for (i = 0; i < last_word - first_word + 1; i++)
-		eeprom_buff[i] = cpu_to_le16(eeprom_buff[i]);
+		cpu_to_le16s(&eeprom_buff[i]);
 
 	ret_val = hw->nvm.ops.write(hw, first_word,
 				    last_word - first_word + 1, eeprom_buff);