add const to quiet compiler

diff --git a/src/lib/unlang/xlat_expr.c b/src/lib/unlang/xlat_expr.c
index 8f20a6be26d9e5ea7f94ca1788691c4aa2cd570b..e8a01849b791112a1532357e3a94f7bb82c9ef3a 100644 (file)
--- a/src/lib/unlang/xlat_expr.c
+++ b/src/lib/unlang/xlat_expr.c
@@ -1403,7 +1403,7 @@ static xlat_action_t xlat_func_exists(TALLOC_CTX *ctx, fr_dcursor_t *out,
                                     xlat_ctx_t const *xctx,
                                     request_t *request, UNUSED fr_value_box_list_t *in)
 {
-       xlat_exists_inst_t      *inst = talloc_get_type_abort(xctx->inst, xlat_exists_inst_t);
+       xlat_exists_inst_t const *inst = talloc_get_type_abort_const(xctx->inst, xlat_exists_inst_t);
        xlat_exists_rctx_t      *rctx;
 
        /*