wmaker: converted macro 'SAME' into a static function
There are some risks associated with the way arguments are used in macros,
and using a function also allows check on the type of arguments and leaves
more room to the compiler for making the best optimisation choice; it also
allows writing easier to read code (and thus, to maintain).
As a side effect, this should also help Coverity in avoiding false positive
bug reports (like #109605 and #109607).
Signed-off-by: Christophe CURIS <christophe.curis@free.fr>