ide-floppy: fold idefloppy_create_test_unit_ready_cmd into idefloppy_open

There's no need for this function since it is used only once.

[bart: ported it over IDE changes]

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