i40e: move enabling icr0 into i40e_update_enable_itr

If we don't have MSI-X enabled, we handle interrupts on all icr0. This
is a special case, so let's move the conditional into
i40e_update_enable_itr() in order to make i40e_napi_poll easier to
read about.
Signed-off-by: NJacob Keller <jacob.e.keller@intel.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_txrx.c

@@ -2243,6 +2243,12 @@ static inline void i40e_update_enable_itr(struct i40e_vsi *vsi,
 	int idx = q_vector->v_idx;
 	int rx_itr_setting, tx_itr_setting;
 
+	/* If we don't have MSIX, then we only need to re-enable icr0 */
+	if (!(vsi->back->flags & I40E_FLAG_MSIX_ENABLED)) {
+		i40e_irq_dynamic_enable_icr0(vsi->back, false);
+		return;
+	}
+
 	vector = (q_vector->v_idx + vsi->base_vector);
 
 	/* avoid dynamic calculation if in countdown mode OR if
@@ -2396,8 +2402,6 @@ int i40e_napi_poll(struct napi_struct *napi, int budget)
 	 */
 	if (!clean_complete)
 		i40e_force_wb(vsi, q_vector);
-	else if (!(vsi->back->flags & I40E_FLAG_MSIX_ENABLED))
-		i40e_irq_dynamic_enable_icr0(vsi->back, false);
 	else
 		i40e_update_enable_itr(vsi, q_vector);