Convert fabric MTU to string for API call

Change-Id: I8cda30d1f26624533d6adda02158d605bf1e76e8
diff --git a/_states/maasng.py b/_states/maasng.py
index c574f22..b71c9d9 100644
--- a/_states/maasng.py
+++ b/_states/maasng.py
@@ -365,7 +365,7 @@
                                                            description=description,
                                                            primary_rack=primary_rack,
                                                            dhcp_on=dhcp_on)
-        ret['comment'] = 'Vlan {0} has' \
+        ret['comment'] = 'Vlan {0} has ' \
                          'been created for {1}'.format(name, fabric)
     elif _rez == 'update':
         _id = __salt__['maasng.list_vlans'](fabric)[vlan]['id']
@@ -378,7 +378,7 @@
                                                            dhcp_on=dhcp_on,
                                                            update=True,
                                                            vlan_id=_id)
-        ret['comment'] = 'Vlan {0} has been' \
+        ret['comment'] = 'Vlan {0} has been ' \
                          'updated for {1}'.format(name, fabric)
     ret['changes'] = changes