ide-floppy: remove struct idefloppy_request_sense_result

While at it, collapse idefloppy_analyze_error() into
idefloppy_request_sense_callback() since the latter was its only user.

Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>