audit: use ktime_get_coarse_real_ts64() for timestamps

Commit c72051d5778a ("audit: use ktime_get_coarse_ts64() for time
access") converted audit's use of current_kernel_time64() to the
new ktime_get_coarse_ts64() function.  Unfortunately this resulted
in incorrect timestamps, e.g. events stamped with the year 1969
despite it being 2018.  This patch corrects this by using
ktime_get_coarse_real_ts64() just like the current_kernel_time64()
wrapper.

Fixes: c72051d5778a ("audit: use ktime_get_coarse_ts64() for time access")
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>

kernel/audit.c

@@ -1721,7 +1721,7 @@ static inline void audit_get_stamp(struct audit_context *ctx,
 				   struct timespec64 *t, unsigned int *serial)
 {
 	if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
-		ktime_get_coarse_ts64(t);
+		ktime_get_coarse_real_ts64(t);
 		*serial = audit_serial();
 	}
 }

kernel/auditsc.c

@@ -1543,7 +1543,7 @@ void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2,
 	context->in_syscall = 1;
 	context->current_state  = state;
 	context->ppid       = 0;
-	ktime_get_coarse_ts64(&context->ctime);
+	ktime_get_coarse_real_ts64(&context->ctime);
 }
 
 /**