Fix rocksdb.unique_check: do not have two threads waiting on the same name

storage/rocksdb/mysql-test/rocksdb/r/unique_check.result

@@ -66,12 +66,12 @@ id	id2	value
 2	1	2
 truncate table t2;
 connection con1;
-set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked1 WAIT_FOR go';
+set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked1 WAIT_FOR go1';
 insert into t1 values (1,1);
 connection default;
 set debug_sync='now WAIT_FOR parked1';
 connection con2;
-set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked2 WAIT_FOR go';
+set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked2 WAIT_FOR go2';
 insert into t2 values (1,1,1);
 connection default;
 set debug_sync='now WAIT_FOR parked2';
@@ -82,7 +82,8 @@ ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 insert into t2 values (2,1,2);
 ERROR HY000: Lock wait timeout exceeded; try restarting transaction
 connection default;
-set debug_sync='now SIGNAL go';
+set debug_sync='now SIGNAL go1';
+set debug_sync='now SIGNAL go2';
 connection con1;
 connection con2;
 connection default;

storage/rocksdb/mysql-test/rocksdb/t/unique_check.test

@@ -102,14 +102,14 @@ truncate table t2;
 
 # 4) simulating T1 GetForUpdate() -> T2 GetForUpdate(). T2 should fail with lock wait timeout. 
 connection con1;
-set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked1 WAIT_FOR go';
+set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked1 WAIT_FOR go1';
 send insert into t1 values (1,1);
 
 connection default;
 set debug_sync='now WAIT_FOR parked1';
 
 connection con2;
-set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked2 WAIT_FOR go';
+set debug_sync='rocksdb.update_write_row_after_unique_check SIGNAL parked2 WAIT_FOR go2';
 send insert into t2 values (1,1,1);
 
 connection default;
@@ -123,7 +123,8 @@ insert into t1 values (1,2);
 insert into t2 values (2,1,2);
 
 connection default;
-set debug_sync='now SIGNAL go';
+set debug_sync='now SIGNAL go1';
+set debug_sync='now SIGNAL go2';
 
 connection con1;
 reap;