Remove usages of "round_to_oldest" configuration

 963__wt_txn_set_timestamp(WT_SESSION_IMPL *session, const char *cfg[])

 964{

 965        WT_CONFIG_ITEM cval;

 966        WT_DECL_RET;

 967        WT_TXN *txn = &session->txn;

 968        wt_timestamp_t ts;

 969

 970        WT_TRET(__wt_txn_context_check(session, true));

 971

 972        /* Look for round_to_oldest configuration. */

    CID 112697 (#1 of 1): Unused value (UNUSED_VALUE)returned_value: Assigning value from __wt_config_gets_def(session, cfg, "round_to_oldest", 0, &cval) to ret here, but that stored value is overwritten before it can be used.

 973        ret = __wt_config_gets_def(session, cfg, "round_to_oldest", 0, &cval);

 974        if (cval.val)

 975                F_SET(txn, WT_TXN_TS_ROUND_READ);

 976

 977        /* Look for a commit timestamp. */

    value_overwrite: Overwriting previous write to ret with value from __wt_config_gets_def(session, cfg, "commit_timestamp", 0, &cval).

 978        ret = __wt_config_gets_def(session, cfg, "commit_timestamp", 0, &cval);