A fix for the broken 4.1-runtime tree.

mysql-test/t/backup.test:
  Backport a patch for sporadically failing myisam.test (and now ps.test)
  from 5.0. The cause was in backup.test not cleaning up tables in
  mysqltest-vardir/tmp after itself.
mysql-test/t/ps.test:
  Add additional protection against possible failure in the middle of
  backup.test

mysql-test/t/backup.test

@@ -51,5 +51,6 @@ unlock tables;
 connection con1;
 reap;
 drop table t5;
+--system rm $MYSQLTEST_VARDIR/tmp/t?.*
 
 # End of 4.1 tests

mysql-test/t/ps.test

@@ -1127,7 +1127,12 @@ show create table mysqltest.t2;
 drop database mysqltest;
 deallocate prepare stmt1;
 deallocate prepare stmt2;
+#
 # CREATE TABLE with DATA DIRECTORY option
+#
+# Protect ourselves from data left in tmp/ by a previos possibly failed
+# test
+--system rm -f $MYSQLTEST_VARDIR/tmp/t1.*
 --disable_query_log
 eval prepare stmt from "create table t1 (c char(10)) data directory='$MYSQLTEST_VARDIR/tmp'";
 --enable_query_log