ide-floppy: disambiguate function names

There were two almost identical function names in ide-floppy.c, which makes
their distinction almost impossible. While ide_floppy_release() cleans up the
object after the last reference to it has been dropped, idefloppy_release() is
the blkdev .release method from struct block_device_operations which releases
that last reference.

Rename ide_floppy_release() to idefloppy_cleanup_obj() in order to make its
purpose more clear.

There should be no functionality change resulting from this patch.

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