rusticl: fix build error with valgrind being enabled
IMPORTANT: due to this depending on a fix in meson, we shouldn't merge this unless the fix needed in meson got backported to stable branches or at least released.
This requires https://github.com/mesonbuild/meson/pull/11024
Closes: #7688 (closed) Fixes: 20c90fed ("rusticl: added") Signed-off-by: Karol Herbst kherbst@redhat.com