i40e: Invoke softirqs after napi_reschedule

The following message is logged from time to time when using i40e:
NOHZ: local_softirq_pending 08

i40e may schedule napi from a workqueue. Afterwards, softirqs are not run
in a deterministic time frame. The problem is the same as what was
described in commit ec13ee80 ("virtio_net: invoke softirqs after
__napi_schedule") and this patch applies the same fix to i40e.
Signed-off-by: NBenjamin Poirier <bpoirier@suse.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

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

@@ -4685,8 +4685,10 @@ static void i40e_detect_recover_hung_queue(int q_idx, struct i40e_vsi *vsi)
 	 */
 	if ((!tx_pending_hw) && i40e_get_tx_pending(tx_ring, true) &&
 	    (!(val & I40E_PFINT_DYN_CTLN_INTENA_MASK))) {
+		local_bh_disable();
 		if (napi_reschedule(&tx_ring->q_vector->napi))
 			tx_ring->tx_stats.tx_lost_interrupt++;
+		local_bh_enable();
 	}
 }