libata: fix kernel-doc param name

Fix libata kernel-doc parameter name.

Warning(linux-2.6.23-git13//drivers/ata/libata-core.c:1415): No description found for parameter 'sgl'
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NJeff Garzik <jeff@garzik.org>

drivers/ata/libata-core.c

@@ -1392,7 +1392,7 @@ static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
  *	@tf: Taskfile registers for the command and the result
  *	@cdb: CDB for packet command
  *	@dma_dir: Data tranfer direction of the command
- *	@sg: sg list for the data buffer of the command
+ *	@sgl: sg list for the data buffer of the command
  *	@n_elem: Number of sg entries
  *	@timeout: Timeout in msecs (0 for default)
  *