Make a test independent of the build options

The number of records in INFORMATION_SCHEMA.COLUMNS depends on the
build options, and could easily change when features are added.
We are not interested in the number of rows returned. The test was
originally added because of problem 15 reported in MDEV-13900
(testing for MDEV-11369 instant ADD COLUMN). The issue was an
assertion failure ut_ad(!rec_is_default_row(rec, index))
in lock_clust_rec_cons_read_sees(), because the 'default row' record
was not being properly ignored by the b-tree cursor.

mysql-test/suite/innodb/r/instant_alter_debug.result

@@ -32,10 +32,10 @@ pk	f
 CREATE TABLE t4 (pk INT PRIMARY KEY) ENGINE=InnoDB;
 INSERT INTO t4 VALUES (0);
 ALTER TABLE t4 ADD COLUMN b INT;
-SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
+SELECT COUNT(*)>0 FROM INFORMATION_SCHEMA.COLUMNS
 LEFT JOIN t4 ON (NUMERIC_SCALE = pk);
-COUNT(*)
-953
+COUNT(*)>0
+1
 SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL enter WAIT_FOR delete';
 ALTER TABLE t4 ADD COLUMN c INT;
 connect  dml,localhost,root,,;

mysql-test/suite/innodb/t/instant_alter_debug.test

@@ -38,7 +38,7 @@ SELECT * FROM t3;
 CREATE TABLE t4 (pk INT PRIMARY KEY) ENGINE=InnoDB;
 INSERT INTO t4 VALUES (0);
 ALTER TABLE t4 ADD COLUMN b INT;
-SELECT COUNT(*) FROM INFORMATION_SCHEMA.COLUMNS
+SELECT COUNT(*)>0 FROM INFORMATION_SCHEMA.COLUMNS
 LEFT JOIN t4 ON (NUMERIC_SCALE = pk);
 SET DEBUG_SYNC='innodb_inplace_alter_table_enter SIGNAL enter WAIT_FOR delete';
 --send