[PATCH v2] mfd: wm831x: add null check before pointer dereference

["Gustavo A. R. Silva" <garsilva@embeddedor.com>]

Add NULL check before dereferencing pointer of_id in order to avoid
a potential NULL pointer dereference.

Addresses-Coverity-ID: 1408830
Cc: Lee Jones <lee.jones@linaro.org>
Cc: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
---
Changes in v2:
 Update error log and return value.

 drivers/mfd/wm831x-spi.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/mfd/wm831x-spi.c b/drivers/mfd/wm831x-spi.c
index c332e28..018ce65 100644
--- a/drivers/mfd/wm831x-spi.c
+++ b/drivers/mfd/wm831x-spi.c
@@ -34,6 +34,10 @@ static int wm831x_spi_probe(struct spi_device *spi)
 
 	if (spi->dev.of_node) {
 		of_id = of_match_device(wm831x_of_match, &spi->dev);
+		if (!of_id) {
+			dev_err(&spi->dev, "Failed to match device\n");
+			return -ENODEV;
+		}
 		type = (enum wm831x_parent)of_id->data;
 	} else {
 		type = (enum wm831x_parent)id->driver_data;
-- 
2.5.0