Fix to make ndb_multi.test (Bug #15401 NDB lock problems) more predictable

mysql-test/r/ndb_multi.result

@@ -30,6 +30,7 @@ create table t1 (a int) engine=ndbcluster;
 insert into t1 value (2);
 select * from t1;
 ERROR HY000: Got error 241 'Invalid schema object version' from ndbcluster
+flush table t1;
 select * from t1;
 a
 2

mysql-test/t/ndb_multi.test

@@ -40,6 +40,7 @@ connection server1;
 # Currently a retry is required remotely
 --error 1296
 select * from t1;
+flush table t1;
 select * from t1;
 
 # Connect to server2 and use the tables from there