Post-merge fixes: rocksdb.check_ignore_unknown_options

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

 select variable_name, variable_value from information_schema.global_variables where variable_name="rocksdb_ignore_unknown_options";
 variable_name	variable_value
 ROCKSDB_IGNORE_UNKNOWN_OPTIONS	ON
+FOUND 1 /RocksDB: Compatibility check against existing database options failed/ in my_restart.err
 select variable_name, variable_value from information_schema.global_variables where variable_name="rocksdb_ignore_unknown_options";
 variable_name	variable_value
 ROCKSDB_IGNORE_UNKNOWN_OPTIONS	ON

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

@@ -4,12 +4,13 @@ let $restart_file= $MYSQLTEST_VARDIR/tmp/mysqld.1.expect;
 let $error_log= $MYSQLTEST_VARDIR/log/my_restart.err;
 select variable_name, variable_value from information_schema.global_variables where variable_name="rocksdb_ignore_unknown_options";
 
---exec find $MYSQLD_DATADIR/.rocksdb/OPTIONS* | sort -n | tail -1 | xargs -0 -I {} -t sh -c "echo hello=world>>{}"
+--exec find $MYSQLD_DATADIR/#rocksdb/OPTIONS* | sort -n | tail -1 | xargs -0 -I {} -t sh -c "echo hello=world>>{}"
 
 --exec echo "wait" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
 --shutdown_server 10
+
 --error 1
---exec $MYSQLD_CMD --rocksdb_ignore_unknown_options=0 --loose-console > $error_log 2>&1
+--exec $MYSQLD_CMD --plugin_load=$HA_ROCKSDB_SO --rocksdb_ignore_unknown_options=0 --loose-console --log-error=$error_log
 
 let SEARCH_FILE= $error_log;
 let SEARCH_PATTERN= RocksDB: Compatibility check against existing database options failed;
@@ -17,5 +18,5 @@ let SEARCH_PATTERN= RocksDB: Compatibility check against existing database optio
 --enable_reconnect
 --exec echo "restart" > $restart_file
 --source include/wait_until_connected_again.inc
---exec find $MYSQLD_DATADIR/.rocksdb/OPTIONS* | sort -n | tail -1 | xargs -0 -I {} -t sh -c "sed -i '/hello=world/d' {}"
+--exec find $MYSQLD_DATADIR/#rocksdb/OPTIONS* | sort -n | tail -1 | xargs -0 -I {} -t sh -c "sed -i '/hello=world/d' {}"
 select variable_name, variable_value from information_schema.global_variables where variable_name="rocksdb_ignore_unknown_options";