The devm_gen_pool_create() function never returns NULL, it returns
error pointers.
Fixes: 4cc9b565454b ("drm/vboxvideo: Use devm_gen_pool_create")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211118111233.GA1147@kili
        /* Create guest-heap mem-pool use 2^4 = 16 byte chunks */
        vbox->guest_pool = devm_gen_pool_create(vbox->ddev.dev, 4, -1,
                                                "vboxvideo-accel");
-       if (!vbox->guest_pool)
-               return -ENOMEM;
+       if (IS_ERR(vbox->guest_pool))
+               return PTR_ERR(vbox->guest_pool);
 
        ret = gen_pool_add_virt(vbox->guest_pool,
                                (unsigned long)vbox->guest_heap,