ata: pata_artop: Repair possible copy/paste issue in 'artop_6210_qc_defer()'s header

Fixes the following W=1 kernel build warning(s):

drivers/ata/pata_artop.c:278: warning: expecting prototype for artop_6210_qc_defer(). Prototype was for artop6210_qc_defer() instead

Cc: Jens Axboe <[e-mail]>
Cc: Andre Hedrick <[e-mail]>
Cc: Thibaut VARENE <[e-mail]>
Cc: Alessandro Zummo <[e-mail]>
Cc: [e-mail]
Signed-off-by: Lee Jones <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/ata/pata_artop.c

···
 }
 
 /**
- *	artop_6210_qc_defer	-	implement serialization
+ *	artop6210_qc_defer	-	implement serialization
  *	@qc: command
  *
  *	Issue commands per host on this chip.