data provider: micro-optimization

skip availability check when updating the node timestamp.
If the update succeeds, the data provider is healthy

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/dataprovider/scheduler.go

@@ -84,11 +84,14 @@ func addScheduledCacheUpdates() error {
 
 func checkDataprovider() {
 	if currentNode != nil {
-		if err := provider.updateNodeTimestamp(); err != nil {
+		err := provider.updateNodeTimestamp()
+		if err != nil {
 			providerLog(logger.LevelError, "unable to update node timestamp: %v", err)
 		} else {
 			providerLog(logger.LevelDebug, "node timestamp updated")
 		}
+		metric.UpdateDataProviderAvailability(err)
+		return
 	}
 	err := provider.checkAvailability()
 	if err != nil {