b=17310

b=17310

Small add on patch for this bug.

- quiet last fail_loc in ptlrpc_check_set() which is supposed to turn fail_loc off. We do not need
it in log;

- make sure that ptlrpc_set_next_timeout() yields 1s timeout (instead of 0s) for the set with rpcs
in "unregistering" stage to prevent ptlrpcd from sleeping forever and hanging in test_45;

- some comment cleanups in ptlrpc_set_next_timeout();

- in ptlrpc_unregister_reply() hit fail_loc and engage long unlink only for asyn == 1 which is
connect in test_45. This makes sure that synchronous rpcs such as enqueue to mgs will not make
test_45 longer than expected;

- in ptlrpcd() make sure that we do not sleep on 0 timeout.