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/infiniband/core/cm.c b/drivers/infiniband/core/cm.c
index 8b72f392..c889aae 100644
--- a/drivers/infiniband/core/cm.c
+++ b/drivers/infiniband/core/cm.c
@@ -3659,7 +3659,7 @@
 	.release = cm_release_port_obj
 };
 
-static char *cm_devnode(struct device *dev, mode_t *mode)
+static char *cm_devnode(struct device *dev, umode_t *mode)
 {
 	if (mode)
 		*mode = 0666;