[rygel] media-export: Avoid some unnecessary copies.

[Krzesimir Nowak <krnowak src gnome org>]

commit 96627256aedeb49c772e510e662278b6fe1d17c1
Author: Krzesimir Nowak <krnowak openismus com>
Date:   Mon Feb 4 16:41:12 2013 +0100

    media-export: Avoid some unnecessary copies.

 .../rygel-media-export-media-cache.vala            |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/plugins/media-export/rygel-media-export-media-cache.vala b/src/plugins/media-export/rygel-media-export-media-cache.vala
index 7e89ac9..a442e66 100644
--- a/src/plugins/media-export/rygel-media-export-media-cache.vala
+++ b/src/plugins/media-export/rygel-media-export-media-cache.vala
@@ -847,7 +847,7 @@ public class Rygel.MediaExport.MediaCache : Object {
         string right_sql_string = MediaCache.search_expression_to_sql
                                         (expression.operand2,
                                          args);
-        string operator_sql_string = "OR";
+        unowned string operator_sql_string = "OR";
 
         if (expression.op == LogicalOperator.AND) {
             operator_sql_string = "AND";
@@ -1016,7 +1016,7 @@ public class Rygel.MediaExport.MediaCache : Object {
         string? collate;
         var builder = new StringBuilder("ORDER BY ");
         var fields = sort_criteria.split (",");
-        foreach (var field in fields) {
+        foreach (unowned string field in fields) {
             try {
                 var column = MediaCache.map_operand_to_column
                                         (field[1:field.length],