dri: dmabuf cap does not rely on winsys multibuffer support

dmabuf cap is client side cap, should not rely on whether window
system support multibuffer (i.e. DRI2 multi plane with modifier).

Acked-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31657>

src/gallium/frontends/dri/dri_screen.c

@@ -646,16 +646,14 @@ dri_init_screen(struct dri_screen *screen,
    if (pscreen->caps.device_protected_context)
       screen->has_protected_context = true;
    screen->has_reset_status_query = pscreen->caps.device_reset_status_query;
-
+   screen->has_multibuffer = has_multibuffer;
 
 #ifdef HAVE_LIBDRM
-   if (has_multibuffer) {
-      int dmabuf_caps = pscreen->caps.dmabuf;
-      if (dmabuf_caps & DRM_PRIME_CAP_IMPORT)
-         screen->dmabuf_import = true;
-      if (screen->dmabuf_import && dmabuf_caps & DRM_PRIME_CAP_EXPORT)
-         screen->has_dmabuf = true;
-   }
+   unsigned dmabuf_caps = pscreen->caps.dmabuf;
+   if (dmabuf_caps & DRM_PRIME_CAP_IMPORT)
+      screen->dmabuf_import = true;
+   if (screen->dmabuf_import && dmabuf_caps & DRM_PRIME_CAP_EXPORT)
+      screen->has_dmabuf = true;
 #endif
 
    return dri_fill_in_modes(screen);

src/gallium/frontends/dri/dri_screen.h

@@ -92,6 +92,7 @@ struct dri_screen
 
    bool throttle;
    bool dmabuf_import;
+   bool has_multibuffer;
 
    struct st_config_options options;
 

src/gallium/frontends/dri/kopper.c

@@ -158,7 +158,7 @@ kopper_get_pixmap_buffer(struct dri_drawable *drawable,
 
 #ifndef GLX_USE_APPLE
    drawable->image = loader_dri3_get_pixmap_buffer(conn, pixmap, screen,
-                                                   fourcc, drawable->screen->dmabuf_import, &width, &height, drawable);
+                                                   fourcc, drawable->screen->has_multibuffer, &width, &height, drawable);
 #else
    drawable->image = NULL;
 #endif