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/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c
index a989356..94f6566 100644
--- a/drivers/usb/misc/legousbtower.c
+++ b/drivers/usb/misc/legousbtower.c
@@ -269,7 +269,7 @@
 	.llseek =	tower_llseek,
 };
 
-static char *legousbtower_devnode(struct device *dev, mode_t *mode)
+static char *legousbtower_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "usb/%s", dev_name(dev));
 }