libata: fix kernel-doc warnings

Fix libata kernel-doc warnings:

Warning(linux-next-20090120//drivers/ata/libata-core.c:4720): Excess function parameter 'dev' description in 'ata_qc_new'
Warning(linux-next-20090120//drivers/ata/libata-scsi.c:428): No description found for parameter 'ap'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 88c2428..574715d 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4709,8 +4709,7 @@
 
 /**
  *	ata_qc_new - Request an available ATA command, for queueing
- *	@ap: Port associated with device @dev
- *	@dev: Device from whom we request an available command structure
+ *	@ap: target port
  *
  *	LOCKING:
  *	None.