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>