stats: always free log

We always want to free the open file log if fopen() succeeded. Independently
of if fgets() succeeds or fails.

CID 1326055

https://bugzilla.gnome.org/show_bug.cgi?id=756864

tools/gst-stats.c

@@ -836,10 +836,10 @@ collect_stats (const gchar * filename)
           }
         }
       }
-      fclose (log);
     } else {
       GST_WARNING ("empty log");
     }
+    fclose (log);
   }
 }