gluon-client-bridge, gluon-mesh-batman-adv-core: make macaddr variable local in upgrade script

package/gluon-client-bridge/luasrc/lib/gluon/upgrade/320-gluon-client-bridge-wireless

@@ -25,7 +25,7 @@ local function configure_client(config, radio, index, suffix)
     return
   end
 
-  macaddr = util.get_wlan_mac(radio, index, 1)
+  local macaddr = util.get_wlan_mac(radio, index, 1)
   if not macaddr then
     return
   end

package/gluon-mesh-batman-adv-core/luasrc/lib/gluon/upgrade/320-gluon-mesh-batman-adv-core-wireless

@@ -33,7 +33,7 @@ local function configure_ibss(config, radio, index, suffix, disabled)
     return
   end
 
-  macaddr = util.get_wlan_mac(radio, index, 3)
+  local macaddr = util.get_wlan_mac(radio, index, 3)
   if not macaddr then
     return
   end
@@ -88,7 +88,7 @@ local function configure_mesh(config, radio, index, suffix, disabled)
     return
   end
 
-  macaddr = util.get_wlan_mac(radio, index, 2)
+  local macaddr = util.get_wlan_mac(radio, index, 2)
   if not macaddr then
     return
   end