cluster: extend usage of the ZoneRegionsFileName constant

Signed-off-by: Alejandro Mery <amery@jpi.io>

pkg/cluster/regions.go

@@ -191,7 +191,7 @@ func (z *Zone) SyncRegions() error {
 }
 
 func (z *Zone) syncZoneRegions() error {
-	name := filepath.Join(z.Name, "regions")
+	name := filepath.Join(z.Name, ZoneRegionsFileName)
 
 	if len(z.Regions) > 0 {
 		var buf bytes.Buffer
@@ -210,7 +210,7 @@ func (z *Zone) syncZoneRegions() error {
 // SyncRegions writes to the file system the regions covered
 // by this meta-region
 func (r *Region) SyncRegions() error {
-	name := filepath.Join(r.Name, "regions")
+	name := filepath.Join(r.Name, ZoneRegionsFileName)
 
 	if len(r.Regions) > 0 {
 		var buf bytes.Buffer