lsfd: fix use-after-free and resource leak [coverity scan]

lsfd: fix use-after-free and resource leak [coverity scan]

>>>     CID 374363:  Memory - illegal accesses  (USE_AFTER_FREE)
>>>     Dereferencing freed pointer "t".
764                             snprintf(parser->errmsg, ERRMSG_LEN,
765                                      _("error: unsupported column data type: %d, column: %s"),
766                                      jtype, t->val.str);

856             default:
857                     warnx("unexpected token type: %d", t->type);
>>>     CID 374360:  Resource leaks  (RESOURCE_LEAK)
>>>     Variable "t" going out of scope leaks the storage it points to.
858                     return NULL;

Signed-off-by: Karel Zak <kzak@redhat.com>