gpg: Fix actual leak and possible leaks in the packet parser.

* g10/packet.h (struct parse_packet_ctx_s): Change LAST_PKT deom a
pointer to its struct.
(init_parse_packet): Adjust for LAST_PKT not being a pointer.
* g10/parse-packet.c (parse): Ditto. Free the last packet before
storing a new one in case of a deep link.
(parse_ring_trust): Adjust for LAST_PKT not being a pointer.
* g10/free-packet.c (free_packet): Ditto.
* g10/t-keydb-get-keyblock.c (do_test): Release keyblock.
--

Fixes-commit: afa8680908
Signed-off-by: Werner Koch <wk@gnupg.org>

g10/t-keydb-get-keyblock.c

@@ -61,4 +61,5 @@ do_test (int argc, char *argv[])
   TEST_P ("", ! rc);
 
   keydb_release (hd1);
+  release_kbnode (kb1);
 }