sfc: Use generic DMA API, not PCI-DMA API

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 0e57535..8a9f6d4 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -100,7 +100,7 @@
  * @len: Length of this fragment.
  *	This field is zero when the queue slot is empty.
  * @continuation: True if this fragment is not the end of a packet.
- * @unmap_single: True if pci_unmap_single should be used.
+ * @unmap_single: True if dma_unmap_single should be used.
  * @unmap_len: Length of this fragment to unmap
  */
 struct efx_tx_buffer {