i40e: remove extraneous loop in i40e_vsi_wait_queues_disabled

We can simply check both Tx and Rx queues in a single loop, rather than
repeating the loop twice.

Change-ID: Ic06f26b0e3c2620e0e33c1a2999edda488e647ad
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>