drm: sti: remove sti_gem_prime_export hack

Thanks to "drm: prime: Honour O_RDWR during prime-handle-to-fd"
commit we don't need to hack flags anymore.
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Reviewed-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/sti/sti_drv.c

@@ -306,15 +306,6 @@ static const struct file_operations sti_driver_fops = {
 	.release = drm_release,
 };
 
-static struct dma_buf *sti_gem_prime_export(struct drm_device *dev,
-					    struct drm_gem_object *obj,
-					    int flags)
-{
-	/* we want to be able to write in mmapped buffer */
-	flags |= O_RDWR;
-	return drm_gem_prime_export(dev, obj, flags);
-}
-
 static struct drm_driver sti_driver = {
 	.driver_features = DRIVER_HAVE_IRQ | DRIVER_MODESET |
 	    DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
@@ -332,7 +323,7 @@ static struct drm_driver sti_driver = {
 
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
-	.gem_prime_export = sti_gem_prime_export,
+	.gem_prime_export = drm_gem_prime_export,
 	.gem_prime_import = drm_gem_prime_import,
 	.gem_prime_get_sg_table = drm_gem_cma_prime_get_sg_table,
 	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,