ixgbe: move headroom initialization to ixgbe_configure_rx_ring

ixgbe_rx_offset(), that is supposed to initialize the Rx buffer headroom,
relies on __IXGBE_RX_BUILD_SKB_ENABLED flag.

Currently, the callsite of mentioned function is placed incorrectly
within ixgbe_setup_rx_resources() where Rx ring's build skb flag is not
set yet. This causes the XDP_REDIRECT to be partially broken due to
inability to create xdp_frame in the headroom space, as the headroom is
0.

Fix this by moving ixgbe_rx_offset() to ixgbe_configure_rx_ring() after
the flag setting, which happens to be set in ixgbe_set_rx_buffer_len.

Fixes: c0d4e9d ("ixgbe: store the result of ixgbe_rx_offset() onto ixgbe_ring")
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Vishakha Jambekar <vishakha.jambekar@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

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

@@ -4118,6 +4118,8 @@ void ixgbe_configure_rx_ring(struct ixgbe_adapter *adapter,
 #endif
 	}
 
+	ring->rx_offset = ixgbe_rx_offset(ring);
+
 	if (ring->xsk_pool && hw->mac.type != ixgbe_mac_82599EB) {
 		u32 xsk_buf_len = xsk_pool_get_rx_frame_size(ring->xsk_pool);
 
@@ -6578,7 +6580,6 @@ int ixgbe_setup_rx_resources(struct ixgbe_adapter *adapter,
 
 	rx_ring->next_to_clean = 0;
 	rx_ring->next_to_use = 0;
-	rx_ring->rx_offset = ixgbe_rx_offset(rx_ring);
 
 	/* XDP RX-queue info */
 	if (xdp_rxq_info_reg(&rx_ring->xdp_rxq, adapter->netdev,