LP:680682 - subselect_cache.test fails with valgrind build and --ps-protocol

5.3 built with ./BUILD/compile-amd64-valgrind-max cause additional warnings for subselect_cache.test in ps-protocol:

CURRENT_TEST: main.subselect_cache
— /home/bell/maria/bzr/work-maria-5.3-test/mysql-test/r/subselect_cache.result 2010-11-23 23:09:05.787332000 +0200
+++ /home/bell/maria/bzr/work-maria-5.3-test/mysql-test/r/subselect_cache.reject 2010-11-23 23:14:37.188764811 +0200
@@ -3309,4 +3309,6 @@
 GROUP BY field3
 HAVING (field3 <= 'h' AND field2 != 4) ;
 field2 field3
+Warnings:
+Warning 1292 Truncated incorrect DOUBLE value: 'h'
 drop tables t1, t2, t3;

mysqltest: Result length mismatch