sysinfo: Remove get_monotonic_boottime()

get_monotonic_boottime() is deprecated because it uses the old 'timespec'
structure. This replaces one of the last callers with a call to
ktime_get_boottime.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: y2038@lists.linaro.org
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Link: https://lkml.kernel.org/r/20180618150114.849216-1-arnd@arndb.de

kernel/sys.c

@@ -2512,11 +2512,11 @@ static int do_sysinfo(struct sysinfo *info)
 {
 	unsigned long mem_total, sav_total;
 	unsigned int mem_unit, bitcount;
-	struct timespec tp;
+	struct timespec64 tp;
 
 	memset(info, 0, sizeof(struct sysinfo));
 
-	get_monotonic_boottime(&tp);
+	ktime_get_boottime_ts64(&tp);
 	info->uptime = tp.tv_sec + (tp.tv_nsec ? 1 : 0);
 
 	get_avenrun(info->loads, 0, SI_LOAD_SHIFT - FSHIFT);