staging/lustre/obdclass: fix false used uninitialized warning

Got below warning when building lustre with 4.7.3.
drivers/staging/lustre/lustre/obdclass/llog_test.c: In function ‘
llog_test_init’:
drivers/staging/lustre/lustre/obdclass/llog_test.c:1058:28: warning: ‘
lvars.module_vars’ is used uninitialized in this function
[-Wuninitialized]
Signed-off-by: NPeng Tao <bergwolf@gmail.com>
Signed-off-by: NAndreas Dilger <andreas.dilger@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/obdclass/llog_test.c

@@ -1048,7 +1048,7 @@ static struct obd_ops llog_obd_ops = {
 
 static int __init llog_test_init(void)
 {
-	struct lprocfs_static_vars lvars;
+	struct lprocfs_static_vars uninitialized_var(lvars);
 
 	lprocfs_llog_test_init_vars(&lvars);
 	return class_register_type(&llog_obd_ops, NULL,