update outdated comment on encodeTags function

Author: francoispqt

pkg/gce-cloud-provider/compute/gce-compute.go

@@ -1113,8 +1113,8 @@ func removeCryptoKeyVersion(kmsKey string) string {
 	return kmsKey
 }
 
-// encodeTags encodes requested volume or snapshot tags into JSON string, as GCE does
-// not support tags on GCE PDs and Snapshots and we use Description field as fallback.
+// encodeTags encodes requested volume or snapshot tags into JSON string, suitable for putting into
+// the PD or Snapshot Description field.
 func encodeTags(tags map[string]string) (string, error) {
 	if len(tags) == 0 {
 		// No tags -> empty JSON