staging/lustre: use 64-bit time LNetCtl()

This ioctl function passes a 64-bit time argument but then performs
a computation with a 32-bit get_seconds() value.

In order to avoid overflow here, this changes the code to use
64-bit math and ktime_get_real_seconds().
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lnet/lnet/api-ni.c

@@ -1343,6 +1343,7 @@ LNetCtl(unsigned int cmd, void *arg)
 	lnet_process_id_t id = {0};
 	lnet_ni_t *ni;
 	int rc;
+	unsigned long secs_passed;
 
 	LASSERT(the_lnet.ln_init);
 	LASSERT(the_lnet.ln_refcount > 0);
@@ -1370,10 +1371,9 @@ LNetCtl(unsigned int cmd, void *arg)
 				      &data->ioc_nid, &data->ioc_flags,
 				      &data->ioc_priority);
 	case IOC_LIBCFS_NOTIFY_ROUTER:
+		secs_passed = (ktime_get_real_seconds() - data->ioc_u64[0]);
 		return lnet_notify(NULL, data->ioc_nid, data->ioc_flags,
-				   cfs_time_current() -
-				   cfs_time_seconds(get_seconds() -
-						    (time_t)data->ioc_u64[0]));
+				   jiffies - secs_passed * HZ);
 
 	case IOC_LIBCFS_PORTALS_COMPATIBILITY:
 		/* This can be removed once lustre stops calling it */