i40e: Queues are reserved despite "Invalid argument" error

Added a new local variable in the i40e_setup_tc function named
old_queue_pairs so num_queue_pairs can be restored to the correct
value in case configuring queue channels fails. Additionally, moved
the exit label in the i40e_setup_tc function so the if (need_reset)
block can be executed.
Also, fixed data packing in the i40e_setup_tc function.

Signed-off-by: Adam Ludkiewicz <adam.ludkiewicz@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Author: aludkiew

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -6846,10 +6846,12 @@ static int i40e_setup_tc(struct net_device *netdev, void *type_data)
 	struct i40e_pf *pf = vsi->back;
 	u8 enabled_tc = 0, num_tc, hw;
 	bool need_reset = false;
+	int old_queue_pairs;
 	int ret = -EINVAL;
 	u16 mode;
 	int i;
 
+	old_queue_pairs = vsi->num_queue_pairs;
 	num_tc = mqprio_qopt->qopt.num_tc;
 	hw = mqprio_qopt->qopt.hw;
 	mode = mqprio_qopt->mode;
@@ -6950,6 +6952,7 @@ static int i40e_setup_tc(struct net_device *netdev, void *type_data)
 		}
 		ret = i40e_configure_queue_channels(vsi);
 		if (ret) {
+			vsi->num_queue_pairs = old_queue_pairs;
 			netdev_info(netdev,
 				    "Failed configuring queue channels\n");
 			need_reset = true;