link executor: don't try to modprobe in mock mode

executor-scripts/linux/link

@@ -45,12 +45,12 @@ pre-up|post-down)
 				echo "Device $IF_VLAN_RAW_DEVICE for $IFACE does not exist"
 				exit 1
 			fi
-		fi
 
 			if ! [ -d /proc/net/vlan ]; then
 				echo "Loading 8021q kernel module for VLAN support"
 				${MOCK} modprobe 8021q
 			fi
+		fi
 
 		${MOCK} ip link $ADD_DEL link "$IF_VLAN_RAW_DEVICE" name "$IFACE" type vlan id "$IF_VLAN_ID"
 		[ "$UP_DOWN" = "down" ] && exit 0