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/hid/usbhid/usbkbd.c b/drivers/hid/usbhid/usbkbd.c
index bdc7b09..bb14c82 100644
--- a/drivers/hid/usbhid/usbkbd.c
+++ b/drivers/hid/usbhid/usbkbd.c
@@ -196,11 +196,11 @@
 		return -1;
 	if (!(kbd->led = usb_alloc_urb(0, GFP_KERNEL)))
 		return -1;
-	if (!(kbd->new = usb_buffer_alloc(dev, 8, GFP_ATOMIC, &kbd->new_dma)))
+	if (!(kbd->new = usb_alloc_coherent(dev, 8, GFP_ATOMIC, &kbd->new_dma)))
 		return -1;
 	if (!(kbd->cr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL)))
 		return -1;
-	if (!(kbd->leds = usb_buffer_alloc(dev, 1, GFP_ATOMIC, &kbd->leds_dma)))
+	if (!(kbd->leds = usb_alloc_coherent(dev, 1, GFP_ATOMIC, &kbd->leds_dma)))
 		return -1;
 
 	return 0;
@@ -210,9 +210,9 @@
 {
 	usb_free_urb(kbd->irq);
 	usb_free_urb(kbd->led);
-	usb_buffer_free(dev, 8, kbd->new, kbd->new_dma);
+	usb_free_coherent(dev, 8, kbd->new, kbd->new_dma);
 	kfree(kbd->cr);
-	usb_buffer_free(dev, 1, kbd->leds, kbd->leds_dma);
+	usb_free_coherent(dev, 1, kbd->leds, kbd->leds_dma);
 }
 
 static int usb_kbd_probe(struct usb_interface *iface,