ata: libata-scsi: pass the whole mode page to the MODE SELECT handlers

ata_scsi_mode_select_xlat() strips the mode page header before calling
the mode page handlers, which report the position of an invalid field
as an offset relative to the mode page data. It then converts this
offset into an offset in the parameter list by adding the length of the
mode parameter header and of the block descriptors, but not the length
of the mode page header. As a result, the FIELD POINTER of the INVALID
FIELD IN PARAMETER LIST sense data points 2 bytes (page_0 format) or 4
bytes (sub_page format) before the byte that is actually invalid. For
example, changing byte 3 of the caching mode page in a MODE SELECT(10)
parameter list without block descriptors reports byte 9 instead of
byte 11.

Pass the whole mode page, starting with its mode page header, to the
handlers instead, like the ata_msense_*() functions, which generate the
whole mode page. Offsets in buf are then the byte numbers of the mode
page, as used in the mode page definitions of SPC, SBC and SAT, the
handlers can compare buf with the mode page generated by the matching
ata_msense_*() function without adjusting offsets, and the conversion
done by ata_scsi_mode_select_xlat() becomes correct. This also allows
reporting an invalid PAGE LENGTH at the PAGE LENGTH field, which was not
part of buf before. As ata_scsi_mode_select_xlat() rejects SUBPAGE CODE
FFh and mode pages with a wrong SPF bit, each handler only gets its mode
page in a single format, so the mode page header length is known.

Document what buf, len and fp are, and the return values, in kernel-doc
comments for all the handlers.

Fixes: 7780081c1f04 ("libata-scsi: Set information sense field for invalid parameter")
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20261103205448.931471-16-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

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