iio: dummy_evgen: fix possible memleak in evgen init

[Pan Bian]

The memory allocated in the function iio_dummy_evgen_create is not
released if it fails to add the evgen device to device hierarchy. This
may result in a memory leak bug.

Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
---
 drivers/iio/dummy/iio_dummy_evgen.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/dummy/iio_dummy_evgen.c b/drivers/iio/dummy/iio_dummy_evgen.c
index efd0005..f96c0a3 100644
--- a/drivers/iio/dummy/iio_dummy_evgen.c
+++ b/drivers/iio/dummy/iio_dummy_evgen.c
@@ -196,7 +196,10 @@ static __init int iio_dummy_evgen_init(void)
 		return ret;
 	device_initialize(&iio_evgen_dev);
 	dev_set_name(&iio_evgen_dev, "iio_evgen");
-	return device_add(&iio_evgen_dev);
+	ret = device_add(&iio_evgen_dev);
+	if (ret)
+		put_device(&iio_evgen_dev);
+	return ret;
 }
 module_init(iio_dummy_evgen_init);
 
-- 
2.7.4