headers_check fix: x86, setup.h

fix the following 'make headers_check' warning:

  usr/include/asm/setup.h:16: extern's make no sense in userspace
  usr/include/asm/setup.h:17: extern's make no sense in userspace
  usr/include/asm/setup.h:23: extern's make no sense in userspace
  usr/include/asm/setup.h:24: extern's make no sense in userspace
  usr/include/asm/setup.h:51: extern's make no sense in userspace
  usr/include/asm/setup.h:52: extern's make no sense in userspace
Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com>

arch/x86/include/asm/setup.h

@@ -5,23 +5,6 @@
 
 #ifndef __ASSEMBLY__
 
-/* Interrupt control for vSMPowered x86_64 systems */
-void vsmp_init(void);
-
-
-void setup_bios_corruption_check(void);
-
-
-#ifdef CONFIG_X86_VISWS
-extern void visws_early_detect(void);
-extern int is_visws_box(void);
-#else
-static inline void visws_early_detect(void) { }
-static inline int is_visws_box(void) { return 0; }
-#endif
-
-extern int wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip);
-extern int wakeup_secondary_cpu_via_init(int apicid, unsigned long start_eip);
 /*
  * Any setup quirks to be performed?
  */
@@ -48,12 +31,6 @@ struct x86_quirks {
 	int (*update_genapic)(void);
 };
 
-extern struct x86_quirks *x86_quirks;
-extern unsigned long saved_video_mode;
-
-#ifndef CONFIG_PARAVIRT
-#define paravirt_post_allocator_init()	do {} while (0)
-#endif
 #endif /* __ASSEMBLY__ */
 
 #ifdef __KERNEL__
@@ -78,6 +55,28 @@ extern unsigned long saved_video_mode;
 #ifndef __ASSEMBLY__
 #include <asm/bootparam.h>
 
+/* Interrupt control for vSMPowered x86_64 systems */
+void vsmp_init(void);
+
+void setup_bios_corruption_check(void);
+
+#ifdef CONFIG_X86_VISWS
+extern void visws_early_detect(void);
+extern int is_visws_box(void);
+#else
+static inline void visws_early_detect(void) { }
+static inline int is_visws_box(void) { return 0; }
+#endif
+
+extern int wakeup_secondary_cpu_via_nmi(int apicid, unsigned long start_eip);
+extern int wakeup_secondary_cpu_via_init(int apicid, unsigned long start_eip);
+extern struct x86_quirks *x86_quirks;
+extern unsigned long saved_video_mode;
+
+#ifndef CONFIG_PARAVIRT
+#define paravirt_post_allocator_init()	do {} while (0)
+#endif
+
 #ifndef _SETUP
 
 /*