[#1388] metrics: Mark nolint:unused metrics

Although these fields could be deleted, I annotated them so that all the
metrics used would be defined in one place.

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

internal/metrics/innerring.go

@@ -17,6 +17,7 @@ type InnerRingServiceMetrics struct {
 	eventDuration     *prometheus.HistogramVec
 	morphCacheMetrics *morphCacheMetrics
 	logMetrics        logger.LogMetrics
+	// nolint: unused
 	appInfo *ApplicationInfo
 }
 

internal/metrics/node.go

@@ -25,6 +25,7 @@ type NodeMetrics struct {
 	morphClient   *morphClientMetrics
 	morphCache    *morphCacheMetrics
 	log           logger.LogMetrics
+	// nolint: unused
 	appInfo *ApplicationInfo
 }