sdl12-compat: fixed watcom build.

From 6a52c16aaedc7f02d7c035817446785232938e6d Mon Sep 17 00:00:00 2001
From: Ozkan Sezer <[EMAIL REDACTED]>
Date: Thu, 29 Apr 2021 00:41:00 +0300
Subject: [PATCH] fixed watcom build.

---
 src/SDL12_compat.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/SDL12_compat.c b/src/SDL12_compat.c
index 932e2b3..c6dc363 100644
--- a/src/SDL12_compat.c
+++ b/src/SDL12_compat.c
@@ -4286,8 +4286,11 @@ DECLSPEC void SDLCALL
 SDL_UnlockYUVOverlay(SDL12_Overlay *overlay12)
 {
     if (overlay12) {
-        const SDL_Rect rect = { 0, 0, overlay12->w, overlay12->h };
         SDL12_YUVData *hwdata = (SDL12_YUVData *) overlay12->hwdata;
+        SDL_Rect rect;
+        rect.x = rect.y = 0;
+        rect.w = overlay12->w;
+        rect.h = overlay12->h;
         if (overlay12->format == SDL12_IYUV_OVERLAY) {
             SDL20_UpdateYUVTexture(hwdata->texture20, &rect,
                                  hwdata->pixels[0], hwdata->pitches[0],