MDEV-16560: [counter] rocksdb.ttl_secondary_read_filtering fail in buildbot

It is not reproducible, but the issue seems to be the same as with
MDEV-20490 and rocksdb.ttl_primary_read_filtering - a compaction caused
by DROP TABLE gets behind and compacts away the expired rows for the next
test. Fix this in the same way.

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

@@ -101,6 +101,7 @@ a	b
 SELECT * FROM t1 FORCE INDEX (kb);
 a	b
 DROP TABLE t1;
+set global rocksdb_compact_cf= 'default';
 # Read filtering index scan tests (None of these queries should return any results)
 CREATE TABLE t1 (
 a int,

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

@@ -121,6 +121,9 @@ SELECT * FROM t1 FORCE INDEX (kb);
 
 DROP TABLE t1;
 
+# Compact away the dropped data
+set global rocksdb_compact_cf= 'default';
+
 --echo # Read filtering index scan tests (None of these queries should return any results)
 CREATE TABLE t1 (
   a int,