printk: Remove ratelimit.h from kernel.h

Decouple kernel.h from ratelimit.h: the global declaration of
printk's ratelimit_state is not needed, and it leads to messy
circular dependencies due to ratelimit.h's (new) adding of a
spinlock_types.h include.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/lib/ratelimit.c b/lib/ratelimit.c
index 69bfcac..5551731 100644
--- a/lib/ratelimit.c
+++ b/lib/ratelimit.c
@@ -9,7 +9,7 @@
  * This file is released under the GPLv2.
  */
 
-#include <linux/kernel.h>
+#include <linux/ratelimit.h>
 #include <linux/jiffies.h>
 #include <linux/module.h>