Disable warnings in partion_alter_myisam

Disabled warnings for directory option as this is depending on compilation
options.

mysql-test/suite/parts/t/partition_alter_myisam.test

@@ -7,12 +7,14 @@
 #
 
 replace_result $MYSQL_TMP_DIR MYSQL_TMP_DIR;
+--disable_warnings
 eval create table t1 ( c1 int, c2 int, c3 varchar(100)) delay_key_write=1
   partition by key(c1) (
     partition p01 data directory = '$MYSQL_TMP_DIR'
                  index directory = '$MYSQL_TMP_DIR',
     partition p02 data directory = '$MYSQL_TMP_DIR'
                  index directory = '$MYSQL_TMP_DIR');
+--enable_warnings
 insert into t1 values (1, 1, repeat('a', 100));
 insert into t1 select rand()*1000, rand()*1000, repeat('b', 100) from t1;
 insert into t1 select rand()*1000, rand()*1000, repeat('b', 100) from t1;