[gnome-system-monitor] Initialize top of tree variable to null

[Robert Roth <robertroth src gnome org>]

commit 070c38cf70e48c2a8de45033ec7e8db65018b523
Author: Robert Roth <robert roth off gmail com>
Date:   Tue May 14 23:59:09 2013 +0300

    Initialize top of tree variable to null

 src/proctable.cpp |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/src/proctable.cpp b/src/proctable.cpp
index 400e4d1..f9ac6ac 100644
--- a/src/proctable.cpp
+++ b/src/proctable.cpp
@@ -410,6 +410,7 @@ proctable_new (ProcmanApp * const app)
         }
     }
     app->tree = proctree;
+    app->top_of_tree = NULL;
     app->last_vscroll_max = 0;
     app->last_vscroll_value = 0;