media: vsp1: Clean up DLM objects on error

If there is an error allocating a display list within a DLM object
the existing display lists are not free'd, and neither is the DL body
pool.

Use the existing vsp1_dlm_destroy() function to clean up on error.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>