macosx/framework: -[VLCMedia length] returns null every time after the first call.

Signed-off-by: Pierre d'Herbemont <pdherbemont@free.fr>

projects/macosx/framework/Sources/VLCMedia.m

@@ -284,8 +284,9 @@ static void HandleMediaSubItemAdded(const libvlc_event_t * event, void * self)
             [self setLength:[VLCTime timeWithNumber:[NSNumber numberWithLongLong:duration]]];
             return [[length retain] autorelease];
         }
-    }
         return [VLCTime nullTime];
+    }
+    return [[length retain] autorelease];
 }
 
 - (VLCTime *)lengthWaitUntilDate:(NSDate *)aDate