USB: avoid using urb->pipe in usbcore

This patch (as946) eliminates many of the uses of urb->pipe in
usbcore.  Unfortunately there will have to be a significant API
change, affecting all USB drivers, before we can remove it entirely.
This patch contents itself with changing only the interface to
usb_buffer_map_sg() and friends: The pipe argument is replaced with a
direction flag.  That can be done easily because those routines get
used in only one place.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 9d08f5a..019ae96 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -1422,13 +1422,13 @@
 #endif
 
 struct scatterlist;
-int usb_buffer_map_sg(const struct usb_device *dev, unsigned pipe,
+int usb_buffer_map_sg(const struct usb_device *dev, int is_in,
 		      struct scatterlist *sg, int nents);
 #if 0
-void usb_buffer_dmasync_sg(const struct usb_device *dev, unsigned pipe,
+void usb_buffer_dmasync_sg(const struct usb_device *dev, int is_in,
 			   struct scatterlist *sg, int n_hw_ents);
 #endif
-void usb_buffer_unmap_sg(const struct usb_device *dev, unsigned pipe,
+void usb_buffer_unmap_sg(const struct usb_device *dev, int is_in,
 			 struct scatterlist *sg, int n_hw_ents);
 
 /*-------------------------------------------------------------------*