- Remove desc_used, which is only ever written to.
- Remove a dead store to reclaimed.
- Don't recycle avail.
- Sort variables according to style(9).
These changes will make a subsequent commit easier to read.
o In iflib_tx_credits_update(), don't bother checking whether the
ift_txd_credits_update method pointer is NULL; _iflib_pre_assert()
asserts upfront that this method has been assigned and functions
like iflib_{fast_intr_rxtx,netmap_timer_adjust,txq_can_drain}()
and _task_fn_tx() were already unconditionally relying on the
method being callable.
c2c5d1e787