Revert "Fix flickering of window when using desktop-fullscreen and borderless window on multiple monitors on Linux. Closes #8186."

This reverts commit 2de2e9d031cf7195ccdcf434538ea6b742035ca4.

The fullscreen state is no longer available to check, and the actual bug this was trying to work around was fixed in https://github.com/libsdl-org/SDL/commit/ad813a65e791d295351e70b2d1c36b06f3853999

src/video/x11/SDL_x11window.c

@@ -655,14 +655,8 @@ int X11_CreateWindow(SDL_VideoDevice *_this, SDL_Window *window, SDL_PropertiesI
         return SDL_SetError("Couldn't create window");
     }
 
-    /* Do not set borderless window if in desktop fullscreen, this causes
-       flickering in multi-monitor setups */
-    if (!((window->pending_flags & SDL_WINDOW_FULLSCREEN) &&
-          (window->flags & SDL_WINDOW_BORDERLESS) &&
-          !window->fullscreen_exclusive)) {
-        SetWindowBordered(display, screen, w,
-                          !(window->flags & SDL_WINDOW_BORDERLESS));
-    }
+    SetWindowBordered(display, screen, w,
+                      !(window->flags & SDL_WINDOW_BORDERLESS));
 
     sizehints = X11_XAllocSizeHints();
     /* Setup the normal size hints */