cdrom: make unregister_cdrom() return void

Now unregister_cdrom() always returns 0.
Make it return void and update all callers that check the return value.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Adrian McMenamin <adrian@mcmen.demon.co.uk>
Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 3960002..fe5aefb 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -2032,9 +2032,8 @@
 
 	kfree(info->buffer);
 	kfree(info->toc);
-	if (devinfo->handle == drive && unregister_cdrom(devinfo))
-		printk(KERN_ERR "%s: %s failed to unregister device from the cdrom "
-				"driver.\n", __FUNCTION__, drive->name);
+	if (devinfo->handle == drive)
+		unregister_cdrom(devinfo);
 	drive->dsc_overlap = 0;
 	drive->driver_data = NULL;
 	blk_queue_prep_rq(drive->queue, NULL);