Change the testcase to not depend on the type of 'this' in the output.
GCC 4.9.2 and GCC 4.8.x have different opinions about that variable's type.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@14780 a5019735-40e9-0310-863c-91ae7b9d1cf9