src: ct_timeout: release policy string and state list

src: ct_timeout: release policy string and state list

=================================================================
==19037==ERROR: LeakSanitizer: detected memory leaks

Direct leak of 18 byte(s) in 2 object(s) allocated from:
    #0 0x7ff6ee6f9810 in strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3a810)
    #1 0x7ff6ee22666d in xstrdup /home/pablo/devel/scm/git-netfilter/nftables/src/utils.c:75
    #2 0x7ff6ee28cce9 in nft_parse /home/pablo/devel/scm/git-netfilter/nftables/src/parser_bison.c:5792
    #3 0x4b903f302c8010a  (<unknown module>)

Direct leak of 16 byte(s) in 1 object(s) allocated from:
    #0 0x7ff6ee7a8330 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9330)
    #1 0x7ff6ee226578 in xmalloc /home/pablo/devel/scm/git-netfilter/nftables/src/utils.c:36

SUMMARY: AddressSanitizer: 34 byte(s) leaked in 3 allocation(s).

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>