igb: fix assignment on big endian machines

The igb driver was trying hard to be sparse correct, but somehow
ended up converting a variable into little endian order and then
tries to OR something with it.

A much plainer way of doing things is to leave all variables and
OR operations in CPU (non-endian) mode, and then convert to
little endian only once, which is what this change does.

This probably fixes a bug that might have been seen only on
big endian systems.
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/igb/igb_main.c

@@ -6276,12 +6276,12 @@ int igb_xmit_xdp_ring(struct igb_adapter *adapter,
 	cmd_type |= len | IGB_TXD_DCMD;
 	tx_desc->read.cmd_type_len = cpu_to_le32(cmd_type);
 
-	olinfo_status = cpu_to_le32(len << E1000_ADVTXD_PAYLEN_SHIFT);
+	olinfo_status = len << E1000_ADVTXD_PAYLEN_SHIFT;
 	/* 82575 requires a unique index per ring */
 	if (test_bit(IGB_RING_FLAG_TX_CTX_IDX, &tx_ring->flags))
 		olinfo_status |= tx_ring->reg_idx << 4;
 
-	tx_desc->read.olinfo_status = olinfo_status;
+	tx_desc->read.olinfo_status = cpu_to_le32(olinfo_status);
 
 	netdev_tx_sent_queue(txring_txq(tx_ring), tx_buffer->bytecount);