[cheese] Return NULL rather than a const empty string

[David King <davidk src gnome org>]

commit 82603a97f2a96294167a260f5ff14bbaed2a24b7
Author: David King <amigadave amigadave com>
Date:   Tue Oct 30 09:35:16 2012 +0000

    Return NULL rather than a const empty string
    
    Fix bug 687042 and bug 687123 by returning NULL from
    cheese_camera_get_recorded_time() rather than a const empty string. The
    returned NULL can be safely freed with g_free(), whereas freeing the
    const string is undefined and leads to a crash with glibc.

 libcheese/cheese-camera.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/libcheese/cheese-camera.c b/libcheese/cheese-camera.c
index 6874858..03c696e 100644
--- a/libcheese/cheese-camera.c
+++ b/libcheese/cheese-camera.c
@@ -1803,6 +1803,6 @@ cheese_camera_get_recorded_time (CheeseCamera *camera)
                             hours, minutes, seconds);
   } else {
     GST_WARNING ("Failed to get time from video filesink from camerabin");
-    return "";
+    return NULL;
   }
 }