sdl12-compat: fix build using c++ compilers.

SDL Commits
1 
From b03ee58d6eddbd6f75d774e235b4b10ac6b6e355 Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Mon, 8 Aug 2022 23:02:56 +0300
Subject: [PATCH] fix build using c++ compilers.

---
 src/SDL12_compat.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index 523dfc33..a607939d 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -6467,7 +6467,7 @@ SDL_GetWMInfo(SDL12_SysWMinfo *info12)
     SDL_SysWMinfo info20;
     SDL_bool temp_window = SDL_FALSE;
     SDL_Window *win20 = VideoWindow20;
-    const SDL_bool do_2on12 = ((info12->version.major == 2) && (info12->version.minor == 0) && (info12->version.major == 2) && (info12->version.patch == 0));
+    const int do_2on12 = ((info12->version.major == 2) && (info12->version.minor == 0) && (info12->version.major == 2) && (info12->version.patch == 0));
     int rc;
 
     if ((info12->version.major > 1) && !do_2on12) {