Post-merge fix for rocksdb.add_index_inplace_sstfilewriter

MariaDB has a scaled-down version of the test so we need to set
@@rocksdb_max_row_locks lower to trigger the desired error

(didn't catch this on test BB run because this test is marked as "big")

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

@@ -14,11 +14,14 @@ select count(b) from t1;
 count(b)
 300000
 ALTER TABLE t1 ADD INDEX kb(b), ALGORITHM=INPLACE;
+set @tmp= @@rocksdb_max_row_locks;
+set session rocksdb_max_row_locks=1000;
 ALTER TABLE t1 ADD INDEX kb_copy(b), ALGORITHM=COPY;
 ERROR HY000: Status error 10 received from RocksDB: Operation aborted: Failed to acquire lock due to max_num_locks limit
 set session rocksdb_bulk_load=1;
 ALTER TABLE t1 ADD INDEX kb_copy(b), ALGORITHM=COPY;
 set session rocksdb_bulk_load=0;
+set session rocksdb_max_row_locks=@tmp;
 SELECT COUNT(*) as c FROM
 (SELECT COALESCE(LOWER(CONV(BIT_XOR(CAST(CRC32(CONCAT_WS('#', `b`, CONCAT(ISNULL(`b`)))) AS UNSIGNED)), 10, 16)), 0) AS crc FROM `t1` FORCE INDEX(`kb`)
 UNION DISTINCT

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

@@ -66,12 +66,15 @@ ALTER TABLE t1 ADD INDEX kb(b), ALGORITHM=INPLACE;
 --disable_warnings
 # now do same index using copy algorithm
 # hitting max row locks (1M)
+set @tmp= @@rocksdb_max_row_locks;
+set session rocksdb_max_row_locks=1000;
 --error ER_RDB_STATUS_GENERAL
 ALTER TABLE t1 ADD INDEX kb_copy(b), ALGORITHM=COPY;
 set session rocksdb_bulk_load=1;
 ALTER TABLE t1 ADD INDEX kb_copy(b), ALGORITHM=COPY;
 set session rocksdb_bulk_load=0;
 --enable_warnings
+set session rocksdb_max_row_locks=@tmp;
 
 # checksum testing
 SELECT COUNT(*) as c FROM