fs/proc/mmu.c: headers butchery

fs/proc/mmu.c consists of only one function which uses only:
1) struct vmalloc_info *
2) struct vm_struct *
3) struct vmalloc_info
4) vmlist
5) VMALLOC_TOTAL, VMALLOC_START, VMALLOC_END
6) read_lock, read_unlock
7) vmlist_lock
8) struct vm_struct

This gives us linux/spinlock.h, asm/pgtable.h, "internal.h", linux/vmalloc.h.
asm/pgtable.h uses PKMAP_BASE on i386, for which asm/highmem.h is needed.
But, linux/highmem.h is actually used to make it compile everywhere.
I'll deal later with this particular i386 surprise.

Cross-compile tested on many archs and configs.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/mmu.c

@@ -8,27 +8,10 @@
  * as published by the Free Software Foundation; either version
  * 2 of the License, or (at your option) any later version.
  */
-
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <linux/time.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/mman.h>
-#include <linux/proc_fs.h>
-#include <linux/mm.h>
-#include <linux/mmzone.h>
-#include <linux/pagemap.h>
-#include <linux/swap.h>
-#include <linux/slab.h>
-#include <linux/smp.h>
-#include <linux/seq_file.h>
-#include <linux/hugetlb.h>
+#include <linux/spinlock.h>
 #include <linux/vmalloc.h>
-#include <asm/uaccess.h>
+#include <linux/highmem.h>
 #include <asm/pgtable.h>
-#include <asm/tlb.h>
-#include <asm/div64.h>
 #include "internal.h"
 
 void get_vmalloc_info(struct vmalloc_info *vmi)