Remove display of join buffer size, test fails when someone changes the minimum

mysql-test/r/index_merge.result

@@ -340,9 +340,6 @@ create table t4 (a int);
 insert into t4 values (1),(4),(3);
 set @save_join_buffer_size=@@join_buffer_size;
 set join_buffer_size= 4000;
-show variables like 'join_buffer_size';
-Variable_name	Value
-join_buffer_size	8200
 explain select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5) 
 from t0 as A force index(i1,i2), t0 as B force index (i1,i2) 
 where (A.key1 < 500000 or A.key2 < 3)

mysql-test/t/index_merge.test

@@ -283,7 +283,6 @@ create table t4 (a int);
 insert into t4 values (1),(4),(3);
 set @save_join_buffer_size=@@join_buffer_size;
 set join_buffer_size= 4000;
-show variables like 'join_buffer_size';
 explain select max(A.key1 + B.key1 + A.key2 + B.key2 + A.key3 + B.key3 + A.key4 + B.key4 + A.key5 + B.key5) 
  from t0 as A force index(i1,i2), t0 as B force index (i1,i2) 
   where (A.key1 < 500000 or A.key2 < 3)