i40e: remove redundant check on vsi->active_vlans

active_vlans is an unsigned long array, hence a null check on this
array is superfluous and can be removed.

Detected with static analysis by smatch:

drivers/net/ethernet/intel/i40e/i40e_debugfs.c:386
  i40e_dbg_dump_vsi_seid() warn: this array is probably
  non-NULL. 'vsi->active_vlans'
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Shannon Nelson <shannon.nelson@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_debugfs.c

@@ -147,7 +147,6 @@ static void i40e_dbg_dump_vsi_seid(struct i40e_pf *pf, int seid)
 		dev_info(&pf->pdev->dev, "        vlan_features = 0x%08lx\n",
 			 (unsigned long int)nd->vlan_features);
 	}
-	if (vsi->active_vlans)
 	dev_info(&pf->pdev->dev,
 		 "    vlgrp: & = %p\n", vsi->active_vlans);
 	dev_info(&pf->pdev->dev,