This fixes two bugs introduced by some 2.5 changes:

- O_NDELAY handling typo in floppy_open()

- handling of failed transfers in floppy_end_request()
  (do equivalent of what 2.4 does)

Without first fix I was getting "floppy0: disk absent or changed during
operation" infinite loop on opening and without second fix, infinite loop
on error retry.

Now floppy driver seems to be (somehow) working :-).