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/block/aoe/aoechr.c b/drivers/block/aoe/aoechr.c
index 5f8e39c..e86d206 100644
--- a/drivers/block/aoe/aoechr.c
+++ b/drivers/block/aoe/aoechr.c
@@ -270,7 +270,7 @@
 	.llseek = noop_llseek,
 };
 
-static char *aoe_devnode(struct device *dev, mode_t *mode)
+static char *aoe_devnode(struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "etherd/%s", dev_name(dev));
 }