SDL: fix SDL_audiocvt.c MSVC build.

SDL Commits
1 
From 0dbf585ace75737b8f5b70772b57045eff588048 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Sat, 26 Apr 2025 05:50:00 +0300
Subject: [PATCH] fix SDL_audiocvt.c MSVC build.

---
 src/audio/SDL_audiocvt.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/audio/SDL_audiocvt.c b/src/audio/SDL_audiocvt.c
index e5435070944e5..d05fd915aa009 100644
--- a/src/audio/SDL_audiocvt.c
+++ b/src/audio/SDL_audiocvt.c
@@ -332,7 +332,7 @@ void ConvertAudio(int num_frames,
                 buf[i] *= gain;
             }
         } else {
-            float *fsrc = (float *)src;
+            const float *fsrc = (const float *)src;
             for (int i = 0; i < total_samples; i++) {
                 buf[i] = fsrc[i] * gain;
             }
@@ -913,7 +913,7 @@ GENERIC_INTERLEAVE_WITH_NULLS_FUNCTION(32)
 static void InterleaveAudioChannels(void *output, const void * const *channel_buffers, int channels, int num_samples, const SDL_AudioSpec *spec)
 {
     bool have_null_channel = false;
-    const void *channels_full[16];
+    void *channels_full[16];
 
     // if didn't specify enough channels, pad out a channel array with NULLs.
     if ((channels >= 0) && (channels < spec->channels)) {