fix: review feedback

services/policies/pkg/engine/opa/engine.go

@@ -24,7 +24,8 @@ type OPA struct {
 
 // NewOPA returns a ready to use opa engine.
 func NewOPA(timeout time.Duration, logger log.Logger, conf config.Engine) (OPA, error) {
-	var mtReader io.Reader = nil
+	var mtReader io.Reader
+
 	if conf.Mimes != "" {
 		mtReader, err := os.Open(conf.Mimes)
 		if err != nil {

services/policies/pkg/engine/opa/rf_mimetype.go

@@ -38,7 +38,7 @@ func RFMimetypeExtensions(f io.Reader) (func(*rego.Rego), error) {
 			}
 		}
 		if err := scanner.Err(); err != nil {
-			panic(err)
+			return nil, err
 		}
 	}