totempg.h: avoid a warning

* include/corosync/totem/totempg.h (struct totempg_group):
Make "group" const.

git-svn-id: http://svn.fedorahosted.org/svn/corosync/trunk@1960 fd59a12c-fef9-0310-b244-a6a79926bd2f

include/corosync/totem/totempg.h

@@ -42,7 +42,7 @@
 #include <corosync/hdb.h>
 
 struct totempg_group {
-	void *group;
+	const void *group;
 	int group_len;
 };