kernel/notifier.c should #include <linux/reboot.h>

Every file should include the headers containing the prototypes for its global
functions (in this case {,un}register_reboot_notifier()).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/notifier.c b/kernel/notifier.c
index 4253f47..643360d 100644
--- a/kernel/notifier.c
+++ b/kernel/notifier.c
@@ -4,6 +4,7 @@
 #include <linux/notifier.h>
 #include <linux/rcupdate.h>
 #include <linux/vmalloc.h>
+#include <linux/reboot.h>
 
 /*
  *	Notifier list for kernel code which wants to be called