[PATCH] headers_check: don't expose PFN stuff to userspace in <asm-i386/setup.h>

The header file <linux/pfn.h> doesn't exist in userspace and probably
shouldn't -- but it's used unconditionally in <asm-i386/setup.h>.  Protect it
with #ifdef __KERNEL__ and move setup.h from $(header-y) to $(unifdef-y) in
Kbuild accordingly.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/asm-i386/Kbuild

 include include/asm-generic/Kbuild.asm
 
-header-y += boot.h debugreg.h ldt.h setup.h ucontext.h
+header-y += boot.h debugreg.h ldt.h ucontext.h
 
-unifdef-y += mtrr.h vm86.h
+unifdef-y += mtrr.h setup.h vm86.h

include/asm-i386/setup.h

@@ -6,6 +6,7 @@
 #ifndef _i386_SETUP_H
 #define _i386_SETUP_H
 
+#ifdef __KERNEL__
 #include <linux/pfn.h>
 
 /*
@@ -13,6 +14,7 @@
  */
 #define MAXMEM_PFN	PFN_DOWN(MAXMEM)
 #define MAX_NONPAE_PFN	(1 << 20)
+#endif
 
 #define PARAM_SIZE 4096
 #define COMMAND_LINE_SIZE 256