v3d: actually root the first BO in a command list in the job

We were passing cl->bo, which is NULL, so v3d_job_add_bo was a no-op.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

src/gallium/drivers/v3d/v3d_cl.c

@@ -74,7 +74,7 @@ v3d_cl_ensure_space_with_branch(struct v3d_cl *cl, uint32_t space)
                 v3d_bo_unreference(&cl->bo);
         } else {
                 /* Root the first RCL/BCL BO in the job. */
-                v3d_job_add_bo(cl->job, cl->bo);
+                v3d_job_add_bo(cl->job, new_bo);
         }
 
         cl->bo = new_bo;