GCC (and Clang) have this useful warning that is not enabled by -Wall or
-Wextra. This will ensure that issues like those fixed in
4da52e36
will trigger warnings.
Reviewed-by: Hendrik Leppkes <h.leppkes@gmail.com>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>