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/input/misc/ati_remote2.c b/drivers/input/misc/ati_remote2.c
index 2124b99..e148749 100644
--- a/drivers/input/misc/ati_remote2.c
+++ b/drivers/input/misc/ati_remote2.c
@@ -589,7 +589,7 @@
 	int i, pipe, maxp;
 
 	for (i = 0; i < 2; i++) {
-		ar2->buf[i] = usb_buffer_alloc(udev, 4, GFP_KERNEL, &ar2->buf_dma[i]);
+		ar2->buf[i] = usb_alloc_coherent(udev, 4, GFP_KERNEL, &ar2->buf_dma[i]);
 		if (!ar2->buf[i])
 			return -ENOMEM;
 
@@ -617,7 +617,7 @@
 
 	for (i = 0; i < 2; i++) {
 		usb_free_urb(ar2->urb[i]);
-		usb_buffer_free(ar2->udev, 4, ar2->buf[i], ar2->buf_dma[i]);
+		usb_free_coherent(ar2->udev, 4, ar2->buf[i], ar2->buf_dma[i]);
 	}
 }