make guard clauses to clearly see success pass

builder/amazon/common/access_config.go

@@ -84,24 +84,24 @@ func (c *AccessConfig) Session() (*session.Session, error) {
 		}
 	}
 
-	if sess, err := session.NewSessionWithOptions(opts); err != nil {
+	sess, err := session.NewSessionWithOptions(opts)
+	if err != nil {
 		return nil, err
-	} else {
-		log.Printf("Found region %s", *sess.Config.Region)
-		c.session = sess
-
-		cp, err := c.session.Config.Credentials.Get()
-		if err != nil {
-			if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "NoCredentialProviders" {
-				return nil, fmt.Errorf("No valid credential sources found for AWS Builder. " +
-					"Please see https://www.packer.io/docs/builders/amazon.html#specifying-amazon-credentials " +
-					"for more information on providing credentials for the AWS Builder.")
-			} else {
-				return nil, fmt.Errorf("Error loading credentials for AWS Provider: %s", err)
-			}
+	}
+	log.Printf("Found region %s", *sess.Config.Region)
+	c.session = sess
+
+	cp, err := c.session.Config.Credentials.Get()
+	if err != nil {
+		if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() == "NoCredentialProviders" {
+			return nil, fmt.Errorf("No valid credential sources found for AWS Builder. " +
+				"Please see https://www.packer.io/docs/builders/amazon.html#specifying-amazon-credentials " +
+				"for more information on providing credentials for the AWS Builder.")
+		} else {
+			return nil, fmt.Errorf("Error loading credentials for AWS Provider: %s", err)
 		}
-		log.Printf("[INFO] AWS Auth provider used: %q", cp.ProviderName)
 	}
+	log.Printf("[INFO] AWS Auth provider used: %q", cp.ProviderName)
 
 	if c.DecodeAuthZMessages {
 		DecodeAuthZMessages(c.session)