usb: ehci: Fix a function name in comments

Use dma_map_single() instead of pci_map_single(),
because only dma_map_single() is called here.
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Link: https://lore.kernel.org/r/20210925124920.1564-1-caihuoqing@baidu.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/ehci-hcd.c

@@ -588,7 +588,7 @@ static int ehci_run (struct usb_hcd *hcd)
 	 * hcc_params controls whether ehci->regs->segment must (!!!)
 	 * be used; it constrains QH/ITD/SITD and QTD locations.
 	 * dma_pool consistent memory always uses segment zero.
-	 * streaming mappings for I/O buffers, like pci_map_single(),
+	 * streaming mappings for I/O buffers, like dma_map_single(),
 	 * can return segments above 4GB, if the device allows.
 	 *
 	 * NOTE:  the dma mask is visible through dev->dma_mask, so