drm/ttm: Don't leak a resource on swapout move error

If moving the bo to system for swapout failed, we were leaking
a resource. Fix.

Fixes: bfa3357 ("drm/ttm: allocate resource object instead of embedding it v2")
Cc: Christian König <christian.koenig@amd.com>
Cc: "Christian König" <ckoenig.leichtzumerken@gmail.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.14+
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Reviewed-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230626091450.14757-5-thomas.hellstrom@linux.intel.com

Author: Thomas Hellström

drivers/gpu/drm/ttm/ttm_bo.c

@@ -1167,6 +1167,7 @@ int ttm_bo_swapout(struct ttm_buffer_object *bo, struct ttm_operation_ctx *ctx,
 		ret = ttm_bo_handle_move_mem(bo, evict_mem, true, &ctx, &hop);
 		if (unlikely(ret != 0)) {
 			WARN(ret == -EMULTIHOP, "Unexpected multihop in swaput - likely driver bug.\n");
+			ttm_resource_free(bo, &evict_mem);
 			goto out;
 		}
 	}