fix(sdk): newGranter nil check (#2729)

This pull request makes a targeted fix to the error handling logic in
the `newGranter` function within `sdk/tdf.go`. The change ensures that
if an error occurs while creating the granter, the function immediately
returns the error, preventing further operations on a potentially
invalid object.

Error handling improvement:

* Added an early return in the `newGranter` function to immediately
return if `err` is not nil, improving reliability and preventing
assignment to `g.keyInfoFetcher` when an error occurs. (`sdk/tdf.go`,
[sdk/tdf.goR458-R460](diffhunk://#diff-04aae07cffd4333871c74efd45d47c4e6739b11bf4ebd9a9b5e90376cbf46d08R458-R460)

---------

Co-authored-by: David Mihalcik <dmihalcik@virtru.com>

Author: pflynn-virtru

sdk/tdf.go

@@ -374,9 +374,7 @@ func (tdfConfig *TDFConfig) initKAOTemplate(ctx context.Context, s SDK) error {
 
 	// * Get base key before autoconfigure to condition off of.
 	if tdfConfig.autoconfigure {
-		var g granter
-		var err error
-		g, err = s.newGranter(ctx, tdfConfig, err)
+		g, err := s.newGranter(ctx, tdfConfig)
 		if err != nil {
 			return err
 		}
@@ -448,15 +446,19 @@ func (tdfConfig *TDFConfig) initKAOTemplate(ctx context.Context, s SDK) error {
 	return nil
 }
 
-func (s SDK) newGranter(ctx context.Context, tdfConfig *TDFConfig, err error) (granter, error) {
+func (s SDK) newGranter(ctx context.Context, tdfConfig *TDFConfig) (granter, error) {
 	var g granter
+	var err error
 	if len(tdfConfig.attributeValues) > 0 {
 		g, err = newGranterFromAttributes(s.kasKeyCache, tdfConfig.attributeValues...)
 	} else if len(tdfConfig.attributes) > 0 {
 		g, err = newGranterFromService(ctx, s.kasKeyCache, s.Attributes, tdfConfig.attributes...)
 	}
+	if err != nil {
+		return g, err
+	}
 	g.keyInfoFetcher = s
-	return g, err
+	return g, nil
 }
 
 func (t *TDFObject) Manifest() Manifest {