Fix min in fibheap template

[Jan Hubicka]

Hi,
using min function of fibheap template results in compile error on non-existent
data fields in fibheap node.

Fixed thus.

Bootstrapped/regtested x86_64-linux, comitted.

Honza

        * fibonacci_heap.h (min): Return m_data instead of non-existing data.
Index: fibonacci_heap.h
===================================================================
--- fibonacci_heap.h    (revision 218796)
+++ fibonacci_heap.h    (working copy)
@@ -211,7 +211,7 @@ public:
     if (m_min == NULL)
       return NULL;
 
-    return m_min->data;
+    return m_min->m_data;
   }
 
   /* Replace data associated with NODE and replace it with DATA.  */