st/nine: do not double-close the fd on teardown

As the newly introduced comment says:
 The pipe loader takes ownership of the fd

Thus, there's no need to close it again.

Cc: Patrick Rudolph <siro@das-labor.org>
Cc: Axel Davy <davyaxel0@gmail.com>
Cc: mesa-stable@lists.freedesktop.org>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Axel Davy <davyaxel0@gmail.com>

src/gallium/targets/d3dadapter9/drm.c

@@ -107,7 +107,7 @@ drm_destroy( struct d3dadapter9_context *ctx )
     if (drm->dev)
         pipe_loader_release(&drm->dev, 1);
 
-    close(drm->fd);
+    /* The pipe loader takes ownership of the fd */
     FREE(ctx);
 }