One byte in the local buffer stays uninitialized, at least with the
first iteration, because of the double decrement in the
test_visitor_in_fuzz(). This is what Valgrind does not like and not
critical for the test itself. So, reduce the number of the memory
issues reports.

Signed-off-by: Andrey Shinkevich <andrey.shinkevich@virtuozzo.com>
Message-Id: <1564502498-805893-3-git-send-email-andrey.shinkevich@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>