* scd/apdu.c (get_status_reader): Add ON_WIRE arg, here.
(ct_get_status, pcsc_get_status_direct, pcsc_get_status_wrapped)
(pcsc_get_status, get_status_ccid, my_rapdu_get_status): Likewise.
(reset_pcsc_reader_wrapped, open_pcsc_reader_wrapped): Follow the
change.
(apdu_get_status_internal): It's lower-level driver which judge
it's not needed.  Otherwise, it can't detect the removal.
* scd/ccid-driver.c (ccid_slot_status): After the POWERED_OFF check,
we can skip sending GetSlotStatus packet on wire, when no need.