multi: rename chan DB Open method to OpenForTesting

chainntnfs/test/test_interface.go

@@ -1906,10 +1906,8 @@ func TestInterfaces(t *testing.T, targetBackEnd string) {
 
 		// Initialize a height hint cache for each notifier.
 		tempDir := t.TempDir()
-		db, err := channeldb.Open(tempDir)
-		if err != nil {
-			t.Fatalf("unable to create db: %v", err)
-		}
+		db := channeldb.OpenForTesting(t, tempDir)
+
 		testCfg := channeldb.CacheConfig{
 			QueryDisable: false,
 		}