USB: rename usb_buffer_alloc() and usb_buffer_free() users

For more clearance what the functions actually do,

  usb_buffer_alloc() is renamed to usb_alloc_coherent()
  usb_buffer_free()  is renamed to usb_free_coherent()

They should only be used in code which really needs DMA coherency.

All call sites have been changed accordingly, except for staging
drivers.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Pedro Ribeiro <pedrib@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index d91ad1a..c257940 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -664,15 +664,15 @@
 	urb = usb_alloc_urb(0, GFP_KERNEL);
 	if (!urb)
 		return NULL;
-	buffer = usb_buffer_alloc(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
-		                  &urb->transfer_dma);
+	buffer = usb_alloc_coherent(udev, USB_MAX_RX_SIZE, GFP_KERNEL,
+				    &urb->transfer_dma);
 	if (!buffer) {
 		usb_free_urb(urb);
 		return NULL;
 	}
 
 	usb_fill_bulk_urb(urb, udev, usb_rcvbulkpipe(udev, EP_DATA_IN),
-		          buffer, USB_MAX_RX_SIZE,
+			  buffer, USB_MAX_RX_SIZE,
 			  rx_urb_complete, usb);
 	urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
 
@@ -683,8 +683,8 @@
 {
 	if (!urb)
 		return;
-	usb_buffer_free(urb->dev, urb->transfer_buffer_length,
-		        urb->transfer_buffer, urb->transfer_dma);
+	usb_free_coherent(urb->dev, urb->transfer_buffer_length,
+			  urb->transfer_buffer, urb->transfer_dma);
 	usb_free_urb(urb);
 }