drm/qxl: Remove empty qxl_gem_prime_mmap()

The function qxl_gem_prime_mmap() returns an error. The two callers
of gem_prime_mmap are drm_fbdev_fb_mmap() and drm_gem_dmabuf_mmap(),
which both already handle NULL-callbacks with an error code. So clear
gem_prime_mmap in qxl and remove qxl_gem_prime_mmap().

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210624090500.8320-1-tzimmermann@suse.de

drivers/gpu/drm/qxl/qxl_drv.c

@@ -281,7 +281,6 @@ static struct drm_driver qxl_driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_import_sg_table = qxl_gem_prime_import_sg_table,
-	.gem_prime_mmap = qxl_gem_prime_mmap,
 	.fops = &qxl_fops,
 	.ioctls = qxl_ioctls,
 	.irq_handler = qxl_irq_handler,

drivers/gpu/drm/qxl/qxl_drv.h

@@ -434,8 +434,6 @@ struct drm_gem_object *qxl_gem_prime_import_sg_table(
 int qxl_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map);
 void qxl_gem_prime_vunmap(struct drm_gem_object *obj,
 			  struct dma_buf_map *map);
-int qxl_gem_prime_mmap(struct drm_gem_object *obj,
-				struct vm_area_struct *vma);
 
 /* qxl_irq.c */
 int qxl_irq_init(struct qxl_device *qdev);

drivers/gpu/drm/qxl/qxl_prime.c

@@ -73,9 +73,3 @@ void qxl_gem_prime_vunmap(struct drm_gem_object *obj,
 
 	qxl_bo_vunmap(bo);
 }
-
-int qxl_gem_prime_mmap(struct drm_gem_object *obj,
-		       struct vm_area_struct *area)
-{
-	return -ENOSYS;
-}