switch device_get_devnode() and ->devnode() to umode_t *

both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/usb/core/file.c b/drivers/usb/core/file.c
index 99458c8..d95760d 100644
--- a/drivers/usb/core/file.c
+++ b/drivers/usb/core/file.c
@@ -66,7 +66,7 @@
 	struct class *class;
 } *usb_class;
 
-static char *usb_devnode(struct device *dev, mode_t *mode)
+static char *usb_devnode(struct device *dev, umode_t *mode)
 {
 	struct usb_class_driver *drv;