evaluate: only allow stateful statements in set and map definitions

evaluate: only allow stateful statements in set and map definitions

commit 0acd81559ec9efe2cc3d869bfc8e5a0b4d888456 upstream.

The bison parser doesn't allow this to happen due to grammar
restrictions, but the json input has no such issues.

The bogon input assigns 'notrack' which triggers:
BUG: unknown stateful statement type 19
nft: src/netlink_linearize.c:1061: netlink_gen_stmt_stateful: Assertion `0' failed.

After patch, we get:
Error: map statement must be stateful

Fixes: 07958ec53830 ("json: add set statement list support")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>