Commit VOL-4124. Testcases for device package.

Change-Id: I2fe37621e373f57d9f90da14a0bf0600b8328362
diff --git a/pkg/db/connection.go b/pkg/db/connection.go
index 52cf88b..26cdba3 100644
--- a/pkg/db/connection.go
+++ b/pkg/db/connection.go
@@ -34,12 +34,7 @@
 	"github.com/opencord/voltha-lib-go/v4/pkg/log"
 )
 
-var kvClient *KvStoreClient
-
-// KvStoreClient holds the KVStore info
-type KvStoreClient struct {
-	client kvstore.Client
-}
+var kvClient kvstore.Client
 
 // logger represents the log object
 var logger log.CLogger
@@ -61,8 +56,7 @@
 			logger.Errorw(ctx, "etcd-server-unreachable", log.Fields{"address": address})
 			return nil, errors.New("etcd client unreachable")
 		}
-		kvClient = new(KvStoreClient)
-		kvClient.client = etcdClient
+		kvClient = etcdClient
 		return etcdClient, err
 	}
 	return nil, errors.New("unsupported-kv-store")