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>

net/core/utils.c

@@ -24,6 +24,8 @@
 #include <linux/types.h>
 #include <linux/percpu.h>
 #include <linux/init.h>
+#include <linux/ratelimit.h>
+
 #include <net/sock.h>
 
 #include <asm/byteorder.h>