ide-cd: coding style fixes for VERBOSE_IDE_CD_ERRORS code

* Coding style fixes for VERBOSE_IDE_CD_ERRORS code.

* Add KERN_{ERR,CONT} printk() levels where needed.

This is a preparation for moving this code out of ide-cd.[c,h].

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