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>

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;