[libgee/0.6] Fixed compiler error

[Sebastian Polsterl <sebp src gnome org>]

commit ba87733d757ca45df9d7135d7dce8ffae1a81b00
Author: Sebastian PÃlsterl <sebp k-d-w org>
Date:   Wed Mar 7 23:00:23 2012 +0100

    Fixed compiler error
    
    'NULL' was used instead of 'null'

 gee/hashmap.vala |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/gee/hashmap.vala b/gee/hashmap.vala
index 59766f4..6e8670f 100644
--- a/gee/hashmap.vala
+++ b/gee/hashmap.vala
@@ -236,7 +236,7 @@ public class Gee.HashMap<K,V> : Gee.AbstractMap<K,V> {
 		if (*node != null) {
 			Node<K,V> next = (owned) (*node)->next;
 
-			if (&value != NULL) {
+			if (&value != null) {
 				value = (owned) (*node)->value;
 			}