[glib] gtimezone: Fix two minor leaks in zone_info_unix()

[Philip Withnall <pwithnall src gnome org>]

commit 12de4748082f542f32bbf9c31cf44b9c1ee8279a
Author: Philip Withnall <withnall endlessm com>
Date:   Wed May 16 11:27:25 2018 +0100

    gtimezone: Fix two minor leaks in zone_info_unix()
    
     • A leak of filename on an error path
     • A leak of resolved_identifier if no out_identifier return location
       was provided
    
    The latter was spotted by Peter Bloomfield
    (https://gitlab.gnome.org/GNOME/glib/commit/8945227743a26a4fe6966baaf082dd6516e8a03c#note_111254).
    Thanks!
    
    Signed-off-by: Philip Withnall <withnall endlessm com>
    Reviewed-by: nobody

 glib/gtimezone.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/glib/gtimezone.c b/glib/gtimezone.c
index 896c117bc..72a4916ad 100644
--- a/glib/gtimezone.c
+++ b/glib/gtimezone.c
@@ -457,9 +457,8 @@ zone_info_unix (const gchar  *identifier,
           else
             {
               /* Error */
-              if (out_identifier != NULL)
-                *out_identifier = NULL;
-              return NULL;
+              g_assert (resolved_identifier == NULL);
+              goto out;
             }
         }
       else
@@ -494,12 +493,16 @@ zone_info_unix (const gchar  *identifier,
                                              g_mapped_file_ref (file));
       g_mapped_file_unref (file);
     }
-  g_free (filename);
 
   g_assert (resolved_identifier != NULL);
+
+out:
   if (out_identifier != NULL)
     *out_identifier = g_steal_pointer (&resolved_identifier);
 
+  g_free (resolved_identifier);
+  g_free (filename);
+
   return zoneinfo;
 }