SDL_native_midi: fixed several -Wzero-as-null-pointer-constant warnings from gcc-15

SDL Commits
1 
From 64236646bc50ba7a196c2cc05dad86f0bde3f55f Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 17 Nov 2025 22:25:37 +0300
Subject: [PATCH] fixed several -Wzero-as-null-pointer-constant warnings from
 gcc-15

---
 src/SDL_native_midi_common.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/SDL_native_midi_common.c b/src/SDL_native_midi_common.c
index 6530c73..c716e44 100644
--- a/src/SDL_native_midi_common.c
+++ b/src/SDL_native_midi_common.c
@@ -234,7 +234,7 @@ static MIDIEvent *MIDItoStream(MIDIFile *mididata)
     }
 
     // Make sure the list is properly terminated
-    currentEvent->next = 0;
+    currentEvent->next = NULL;
 
     currentEvent = head->next;
     SDL_free(track);
@@ -396,4 +396,3 @@ NativeMidi_Song *NativeMidi_LoadSong(const char *path)
     SDL_IOStream *io = SDL_IOFromFile(path, "rb");
     return io ? NativeMidi_LoadSong_IO(io, true) : NULL;
 }
-