struct_size() is used to calculate struct linereq size, so explicitly
include overflow.h.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
---
 drivers/gpio/gpiolib-cdev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
index 744734405912..44d864f63130 100644
--- a/drivers/gpio/gpiolib-cdev.c
+++ b/drivers/gpio/gpiolib-cdev.c
@@ -20,6 +20,7 @@
 #include <linux/kfifo.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
+#include <linux/overflow.h>
 #include <linux/pinctrl/consumer.h>
 #include <linux/poll.h>
 #include <linux/rbtree.h>
-- 
2.39.2