--max_granted_credit not respected by fallback credit calculation mechanism

[dhardy]

We (malariacontrol.net) recently had a problem where PFC was too high for some hosts (or in some cases still is). This has resulted in credits being calculated using an alternate mechanism:

        if (pfc > wu.rsc_fpops_bound) {
            log_messages.printf(MSG_NORMAL,
                "[credit] PFC too high: %f\n", pfc*COBBLESTONE_SCALE
            );
            pfc = wu_estimated_pfc(wu, app);
        }

Unfortunately in our case this wasn't always correct. The attached patch at least allows the --max_granted_credit mechanism to still limit the credit granted.

[dhardy]

patch against boinc/sched/credit.cpp