sysinfo: Move struct sysinfo to a separate header file

struct sysinfo is just about the only thing exported to userspace from
<linux/kernel.h>, so move it into a separate header file with a
residual #include in <linux/kernel.h>.
Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org

include/linux/Kbuild

@@ -355,6 +355,7 @@ header-y += suspend_ioctls.h
 header-y += swab.h
 header-y += synclink.h
 header-y += sysctl.h
+header-y += sysinfo.h
 header-y += taskstats.h
 header-y += tcp.h
 header-y += telephony.h

include/linux/kernel.h

 #ifndef _LINUX_KERNEL_H
 #define _LINUX_KERNEL_H
 
+#include <linux/sysinfo.h>
+
 /*
  * 'kernel.h' contains some often-used function prototypes etc
  */
@@ -745,27 +747,8 @@ extern int __build_bug_on_failed;
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
 #endif
 
-struct sysinfo;
 extern int do_sysinfo(struct sysinfo *info);
 
 #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

include/linux/sysinfo.h

+#ifndef _LINUX_SYSINFO_H
+#define _LINUX_SYSINFO_H
+
+#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 /* _LINUX_SYSINFO_H */