SDL_config: return a value from a non-void function

This was an error on clang.

mingw-w64-SDL_mixer/PKGBUILD

@@ -4,7 +4,7 @@ _realname=SDL_mixer
 pkgbase=mingw-w64-${_realname}
 pkgname=${MINGW_PACKAGE_PREFIX}-${_realname}
 pkgver=1.2.12
-pkgrel=8
+pkgrel=9
 pkgdesc="A simple multi-channel audio mixer (mingw-w64)"
 arch=('any')
 mingw_arch=('mingw32' 'mingw64' 'ucrt64' 'clang64')
@@ -28,14 +28,16 @@ source=(https://libsdl.org/projects/SDL_mixer/release/${_realname}-${pkgver}.tar
         fluidsynth-volume.patch
         double-free-crash.patch
         SDL_mixer-find_lib.mingw.patch
-        autoreconf-fix.patch)
+        autoreconf-fix.patch
+        non-void-return-value.patch)
 sha256sums=('1644308279a975799049e4826af2cfc787cad2abb11aa14562e402521f86992a'
             '17bc8704a0e6e66b1a79ae4f58f0fdf0a58ff64db86980b2e0fa7ef352042cdb'
             '7a0fd237def865ec8376ec0f534e75ad4bc1ba6dff66774112cd2f2700ae9a9c'
             '1cc663048ef57c9238a10109bbbbef3b49e2c9d2dbd7c71c7c2f0673a6417e14'
             '912d5b8342eec3626fe61389531f7fe941c9aa6f463cf2681948a739d3c53f35'
             'b204e67c0489dfa9dba32e6f5a6ed554fca6c61d155701af35a41fea5b4db589'
-            'cdd0f47ac42890fe1d8110fa1cd6106b8e143ab8e9ddb7967e891ac149380add')
+            'cdd0f47ac42890fe1d8110fa1cd6106b8e143ab8e9ddb7967e891ac149380add'
+            '20e3e7881960ed86b036ad64c2c4f336d72be0779ce9176bca865b7c35e41253')
 noextract=(${_realname}-${pkgver}.tar.gz)
 
 prepare() {
@@ -50,6 +52,7 @@ prepare() {
   patch -Np1 -i ${srcdir}/double-free-crash.patch
   patch -Np1 -i ${srcdir}/SDL_mixer-find_lib.mingw.patch
   patch -Np1 -i ${srcdir}/autoreconf-fix.patch
+  patch -Np1 -i ${srcdir}/non-void-return-value.patch
 
   #sed -e "/CONFIG_FILE_ETC/s|/etc/timidity.cfg|/etc/timidity++/timidity.cfg|" \
   #    -e "/DEFAULT_PATH/s|/etc/timidity|/etc/timidity++|" \

mingw-w64-SDL_mixer/non-void-return-value.patch

@@ -0,0 +1,11 @@
+--- SDL_mixer-1.2.12/music_mad.c.orig	2021-08-08 19:07:23.524236900 -0700
++++ SDL_mixer-1.2.12/music_mad.c	2021-08-08 19:09:57.811542200 -0700
+@@ -224,7 +224,7 @@
+   if ((mp3_mad->status & MS_playing) == 0) {
+ 	/* We're not supposed to be playing, so send silence instead. */
+ 	memset(stream, 0, len);
+-	return;
++	return len;
+   }
+
+   out = stream;