post_transform_command() call in cdrom_newpc_intr() has no effect because
it is done after the request has already been fully completed (rq->bio and
rq->data are always NULL). It was verified to be true regardless whether
INQUIRY command is using DMA or PIO to transfer data (by using modified
Tejun Heo's test-shortsg.c utility and adding a few printk()-s to ide-cd).
This was uncovered thanks to the "blk_end_request: full I/O completion
handler (take 3)" patch series from Kiyoshi Ueda.