mfd: qcom_rpm: Fix a possible NULL dereference

of_match_device could return NULL, and so cause a NULL pointer
dereference later.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/qcom_rpm.c b/drivers/mfd/qcom_rpm.c
index 207a3bd..1be47ad 100644
--- a/drivers/mfd/qcom_rpm.c
+++ b/drivers/mfd/qcom_rpm.c
@@ -495,6 +495,8 @@
 	}
 
 	match = of_match_device(qcom_rpm_of_match, &pdev->dev);
+	if (!match)
+		return -ENODEV;
 	rpm->data = match->data;
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);