ui/sdl2: start in full screen with grab enabled

QEMU with SDL 1.2 display used to enable keyboard and mouse grab-
bing when started in full screen. The SDL 2.0 code tries to do
the same but fails to enable grabbing because sdl_grab_start(0)
returns early. To do it's work the sdl_grab_start() function
needs a pointer to a sdl2_console structure.

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-id: 20200516072014.7766-7-vr_qemu@t-online.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

ui/sdl2.c

@@ -881,17 +881,16 @@ static void sdl2_display_init(DisplayState *ds, DisplayOptions *o)
         SDL_SetWindowIcon(sdl2_console[0].real_window, icon);
     }
 
-    gui_grab = 0;
-    if (gui_fullscreen) {
-        sdl_grab_start(0);
-    }
-
     mouse_mode_notifier.notify = sdl_mouse_mode_change;
     qemu_add_mouse_mode_change_notifier(&mouse_mode_notifier);
 
     sdl_cursor_hidden = SDL_CreateCursor(&data, &data, 8, 1, 0, 0);
     sdl_cursor_normal = SDL_GetCursor();
 
+    if (gui_fullscreen) {
+        sdl_grab_start(&sdl2_console[0]);
+    }
+
     atexit(sdl_cleanup);
 }