[PATCH] memory-hotplug compile fix

include/linux/memory_hotplug.h:53: warning: 'struct page' declared inside parameter list

(akpm: I tossed in a couple more possibly-needed-sometime struct decls too)
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

include/linux/memory_hotplug.h

@@ -6,6 +6,10 @@
 #include <linux/mmzone.h>
 #include <linux/notifier.h>
 
+struct page;
+struct zone;
+struct pglist_data;
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
  * pgdat resizing functions