SDL_mixer: native_midi_linux_alsa.c: fix build using old gcc.

SDL Commits
1 
From 62bb7bbef52ab27957751f586d03ee9961a4828f Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Wed, 19 Feb 2025 14:40:04 +0300
Subject: [PATCH] native_midi_linux_alsa.c: fix build using old gcc.

---
 src/codecs/native_midi/native_midi_linux_alsa.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/codecs/native_midi/native_midi_linux_alsa.c b/src/codecs/native_midi/native_midi_linux_alsa.c
index a163f231..e7d48231 100644
--- a/src/codecs/native_midi/native_midi_linux_alsa.c
+++ b/src/codecs/native_midi/native_midi_linux_alsa.c
@@ -572,7 +572,7 @@ static int native_midi_player_thread(void *d)
     bool playback_finished = false;
     NativeMidiSong *song = d;
     MIDIEvent *event = song->evtlist;
-
+    int i;
     int queue = ALSA_snd_seq_alloc_named_queue(song->seq, "SDL_Mixer Playback");
     snd_seq_start_queue(song->seq, queue, NULL);
 
@@ -756,7 +756,7 @@ static int native_midi_player_thread(void *d)
     /* Stop all audio */
     /* Some of these are bound to work */
     snd_seq_ev_set_direct(&evt);
-    for (int i = 0; i < MIDI_CHANNELS; i++) {
+    for (i = 0; i < MIDI_CHANNELS; i++) {
         snd_seq_ev_set_controller(&evt, i, MIDI_CTL_SUSTAIN, 0);
         ALSA_snd_seq_event_output_direct(song->seq, &evt);
         snd_seq_ev_set_controller(&evt, i, MIDI_CTL_ALL_NOTES_OFF, 0);