[PATCH] w1: simplify allocation of w1_master

[Rosen Penev <rosenp@gmail.com>]

Convert bus_master to a flexible array member as it's being used as one
with the old C89 + 1 pointer trick.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/w1/w1_int.c | 4 +---
 include/linux/w1.h  | 4 ++--
 2 files changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/w1/w1_int.c b/drivers/w1/w1_int.c
index 19a0ea28e9f3..a0bb97608564 100644
--- a/drivers/w1/w1_int.c
+++ b/drivers/w1/w1_int.c
@@ -31,12 +31,10 @@ static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
 	/*
 	 * We are in process context(kernel thread), so can sleep.
 	 */
-	dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
+	dev = kzalloc_flex(*dev, bus_master, 1);
 	if (!dev)
 		return NULL;

-	dev->bus_master = (struct w1_bus_master *)(dev + 1);
-
 	dev->owner		= THIS_MODULE;
 	dev->max_slave_count	= slave_count;
 	dev->slave_count	= 0;
diff --git a/include/linux/w1.h b/include/linux/w1.h
index 064805bfae3f..7379a9ddefc0 100644
--- a/include/linux/w1.h
+++ b/include/linux/w1.h
@@ -236,9 +236,9 @@ struct w1_master {
 	struct device_driver	*driver;
 	struct device		dev;

-	struct w1_bus_master	*bus_master;
-
 	u32			seq;
+
+	struct w1_bus_master	bus_master[];
 };

 int w1_add_master_device(struct w1_bus_master *master);
--
2.53.0