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/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 9e28b20..61b2d8f 100644
--- a/sound/usb/usbmidi.c
+++ b/sound/usb/usbmidi.c
@@ -1047,8 +1047,8 @@
 static void free_urb_and_buffer(struct snd_usb_midi *umidi, struct urb *urb,
 				unsigned int buffer_length)
 {
-	usb_buffer_free(umidi->dev, buffer_length,
-			urb->transfer_buffer, urb->transfer_dma);
+	usb_free_coherent(umidi->dev, buffer_length,
+			  urb->transfer_buffer, urb->transfer_dma);
 	usb_free_urb(urb);
 }
 
@@ -1099,8 +1099,8 @@
 		pipe = usb_rcvbulkpipe(umidi->dev, ep_info->in_ep);
 	length = usb_maxpacket(umidi->dev, pipe, 0);
 	for (i = 0; i < INPUT_URBS; ++i) {
-		buffer = usb_buffer_alloc(umidi->dev, length, GFP_KERNEL,
-					  &ep->urbs[i]->transfer_dma);
+		buffer = usb_alloc_coherent(umidi->dev, length, GFP_KERNEL,
+					    &ep->urbs[i]->transfer_dma);
 		if (!buffer) {
 			snd_usbmidi_in_endpoint_delete(ep);
 			return -ENOMEM;
@@ -1190,9 +1190,9 @@
 		break;
 	}
 	for (i = 0; i < OUTPUT_URBS; ++i) {
-		buffer = usb_buffer_alloc(umidi->dev,
-					  ep->max_transfer, GFP_KERNEL,
-					  &ep->urbs[i].urb->transfer_dma);
+		buffer = usb_alloc_coherent(umidi->dev,
+					    ep->max_transfer, GFP_KERNEL,
+					    &ep->urbs[i].urb->transfer_dma);
 		if (!buffer) {
 			snd_usbmidi_out_endpoint_delete(ep);
 			return -ENOMEM;