SDL: Use ScreenCount() instead of SDL_GetNumVideoDisplays()

SDL Commits
1 
From b6cf889af45c31b650428e4dbe476daf21be3c9e Mon Sep 17 00:00:00 2001
From: Sam Lantinga <[EMAIL REDACTED]>
Date: Tue, 25 Oct 2022 15:09:43 -0700
Subject: [PATCH] Use ScreenCount() instead of SDL_GetNumVideoDisplays()

The limitation appears to be specific to multi-screen setups
---
 src/video/x11/SDL_x11mouse.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/video/x11/SDL_x11mouse.c b/src/video/x11/SDL_x11mouse.c
index 04c5b8c4784f..96a25a2b9ecc 100644
--- a/src/video/x11/SDL_x11mouse.c
+++ b/src/video/x11/SDL_x11mouse.c
@@ -320,7 +320,7 @@ WarpMouseInternal(Window xwindow, const int x, const int y)
     /* It seems XIWarpPointer() doesn't work correctly on multi-head setups:
      * https://developer.blender.org/rB165caafb99c6846e53d11c4e966990aaffc06cea
      */
-    if (SDL_GetNumVideoDisplays() == 1) {
+    if (ScreenCount(display) == 1) {
         X11_XIGetClientPointer(display, None, &deviceid);
     }
     if (deviceid != 0) {