Fix documentation (pointed out by TheDavidFactor on #-dev)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.4@226304 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/linkedlists.h

@@ -408,7 +408,7 @@ struct {								\
   \brief Checks whether the specified list contains any entries.
   \param head This is a pointer to the list head structure
 
-  Returns non-zero if the list has entries, zero if not.
+  Returns zero if the list has entries, non-zero if not.
  */
 #define	AST_LIST_EMPTY(head)	(AST_LIST_FIRST(head) == NULL)