cciss: fix bug if scsi tape support is disabled

Bug fix. If SCSI tape support is turned off we get an implicit declaration
of cciss_unregister_scsi error in cciss_remove_one.

Signed-off-by: Mike Miller <[e-mail]>
Signed-off-by: Stephen M. Cameron <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/block/cciss.c

···
 		}
 	}
 
+#ifdef CONFIG_CISS_SCSI_TAPE
 	cciss_unregister_scsi(i);	/* unhook from SCSI subsystem */
+#endif
 
 	cciss_shutdown(pdev);