SDL: Fix comment style for old compilers (`//`⇒`/**/`)

From b5d47aa297d508fd1c19eac40a9640a904e62bc4 Mon Sep 17 00:00:00 2001
From: Fredrick Brennan <[EMAIL REDACTED]>
Date: Sun, 28 Nov 2021 23:15:31 -0500
Subject: [PATCH] =?UTF-8?q?Fix=20comment=20style=20for=20old=20compilers?=
 =?UTF-8?q?=20(`//`=E2=87=92`/**/`)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 src/video/x11/SDL_x11window.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/video/x11/SDL_x11window.c b/src/video/x11/SDL_x11window.c
index 51869a6a0b..efaaf5cd76 100644
--- a/src/video/x11/SDL_x11window.c
+++ b/src/video/x11/SDL_x11window.c
@@ -1885,10 +1885,10 @@ int SDL_X11_SetWindowTitle(Display* display, Window xwindow, char* title) {
     if (conv == 0) {
         X11_XSetTextProperty(display, xwindow, &titleprop, XA_WM_NAME);
         X11_XFree(titleprop.value);
-    // we know this can't be a locale error as we checked X locale validity
+    /* we know this can't be a locale error as we checked X locale validity */
     } else if (conv < 0) {
         return SDL_OutOfMemory();
-    } else { // conv > 0
+    } else { /* conv > 0 */
         SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "%d characters were not convertable to the current locale!", conv);
         return 0;
     }