headers: kref.h redux

* remove asm/atomic.h inclusion from kref.h -- not needed, linux/types.h
  is enough for atomic_t
* remove linux/kref.h inclusion from files which do not need it.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/ipc.h

@@ -78,8 +78,6 @@ struct ipc_kludge {
 #define IPCCALL(version,op)	((version)<<16 | (op))
 
 #ifdef __KERNEL__
-
-#include <linux/kref.h>
 #include <linux/spinlock.h>
 
 #define IPCMNI 32768  /* <= MAX_INT limit for ipc arrays (including sysctl changes) */

include/linux/kref.h

@@ -16,7 +16,6 @@
 #define _KREF_H_
 
 #include <linux/types.h>
-#include <asm/atomic.h>
 
 struct kref {
 	atomic_t refcount;

include/linux/nfs_fs.h

@@ -40,7 +40,6 @@
 #ifdef __KERNEL__
 
 #include <linux/in.h>
-#include <linux/kref.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
 #include <linux/rbtree.h>