dlm: Improve a size determination in dlm_recover_waiters_pre()

Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/lock.c

@@ -5119,7 +5119,7 @@ void dlm_recover_waiters_pre(struct dlm_ls *ls)
 	int wait_type, stub_unlock_result, stub_cancel_result;
 	int dir_nodeid;
 
-	ms_stub = kmalloc(sizeof(struct dlm_message), GFP_KERNEL);
+	ms_stub = kmalloc(sizeof(*ms_stub), GFP_KERNEL);
 	if (!ms_stub) {
 		log_error(ls, "dlm_recover_waiters_pre no mem");
 		return;