kernel.h: move BUILD_BUG_ON et al inside __KERNEL__

Recent warning caused by change in BUILD_BUG_ON:

	usr/include/linux/kernel.h:53: userspace cannot call function or variable defined in the kernel

Macros no longer accessible to userspace:

	BUILD_BUG_ON_ZERO, BUILD_BUG_ON_NULL, BUILD_BUG_ON,
	__FUNCTION__, NUMA_BUILD, REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD.

(The last two were in #ifdef CONFIG anyway, so already useless).

Also, avoid silly re-test of __KERNEL__ immediately below.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/kernel.h |   50 +++++++++++++++++++++++--------------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -702,32 +702,6 @@ static inline void ftrace_dump(void) { }
 struct sysinfo;
 extern int do_sysinfo(struct sysinfo *info);
 
-#endif /* __KERNEL__ */
-
-#ifndef __EXPORTED_HEADERS__
-#ifndef __KERNEL__
-#warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
-#endif /* __KERNEL__ */
-#endif /* __EXPORTED_HEADERS__ */
-
-#define SI_LOAD_SHIFT	16
-struct sysinfo {
-	long uptime;			/* Seconds since boot */
-	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
-	unsigned long totalram;		/* Total usable main memory size */
-	unsigned long freeram;		/* Available memory size */
-	unsigned long sharedram;	/* Amount of shared memory */
-	unsigned long bufferram;	/* Memory used by buffers */
-	unsigned long totalswap;	/* Total swap space size */
-	unsigned long freeswap;		/* swap space still available */
-	unsigned short procs;		/* Number of current processes */
-	unsigned short pad;		/* explicit padding for m68k */
-	unsigned long totalhigh;	/* Total high memory size */
-	unsigned long freehigh;		/* Available high memory size */
-	unsigned int mem_unit;		/* Memory unit size in bytes */
-	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
-};
-
 /* Force a compilation error if a constant expression is not a power of 2 */
 #define BUILD_BUG_ON_NOT_POWER_OF_2(n)			\
 	BUILD_BUG_ON((n) == 0 || (((n) & ((n) - 1)) != 0))
@@ -780,4 +754,28 @@ extern int __build_bug_on_failed;
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 #endif
 
+#else /* __KERNEL__ */
+#ifndef __EXPORTED_HEADERS__
+#warning Attempt to use kernel headers from user space, see http://kernelnewbies.org/KernelHeaders
+#endif /* __EXPORTED_HEADERS__ */
+#endif /* !__KERNEL__ */
+
+#define SI_LOAD_SHIFT	16
+struct sysinfo {
+	long uptime;			/* Seconds since boot */
+	unsigned long loads[3];		/* 1, 5, and 15 minute load averages */
+	unsigned long totalram;		/* Total usable main memory size */
+	unsigned long freeram;		/* Available memory size */
+	unsigned long sharedram;	/* Amount of shared memory */
+	unsigned long bufferram;	/* Memory used by buffers */
+	unsigned long totalswap;	/* Total swap space size */
+	unsigned long freeswap;		/* swap space still available */
+	unsigned short procs;		/* Number of current processes */
+	unsigned short pad;		/* explicit padding for m68k */
+	unsigned long totalhigh;	/* Total high memory size */
+	unsigned long freehigh;		/* Available high memory size */
+	unsigned int mem_unit;		/* Memory unit size in bytes */
+	char _f[20-2*sizeof(long)-sizeof(int)];	/* Padding: libc5 uses this.. */
+};
+
 #endif