Problem:
Incorrect md5sum when using ATAPI PIO mode to verify a distro CD.
Root cause: sg traverse problem.
In __atapi_pio_bytes(), if qc->cursg++ is increased and "goto
next_page" is executed, then sg is not updated to the new qc->cursg
and the old sg is overwritten with the new data.
Changes:
- Replace "goto next_page" with "goto next_sg" to make sg updated.