Remove redundant error checks

Signed-off-by: Davor Kapsa <davor.kapsa@gmail.com>

images/archive/importer.go

@@ -197,10 +197,7 @@ func onUntarJSON(r io.Reader, j interface{}) error {
 	if err != nil {
 		return err
 	}
-	if err := json.Unmarshal(b, j); err != nil {
-		return err
-	}
-	return nil
+	return json.Unmarshal(b, j)
 }
 
 func onUntarBlob(ctx context.Context, r io.Reader, store content.Ingester, size int64, ref string) (digest.Digest, error) {