ixgbe: don't do arithmetic operations on bitmasks

Make the calculation of eerd consistent between the read and write functions
by using | instead of + for IXGBE_EEPROM_RW_REG_START

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_common.c

@@ -1125,7 +1125,7 @@ s32 ixgbe_read_eerd_buffer_generic(struct ixgbe_hw *hw, u16 offset,
 	}
 
 	for (i = 0; i < words; i++) {
-		eerd = ((offset + i) << IXGBE_EEPROM_RW_ADDR_SHIFT) +
+		eerd = ((offset + i) << IXGBE_EEPROM_RW_ADDR_SHIFT) |
 		       IXGBE_EEPROM_RW_REG_START;
 
 		IXGBE_WRITE_REG(hw, IXGBE_EERD, eerd);