slimbus: fix a potential NULL pointer dereference in of_qcom_slim_ngd_register

[ Upstream commit 06d5d6b7f9948a89543e1160ef852d57892c750d ]

In case platform_device_alloc fails, the fix returns an error
code to avoid the NULL pointer dereference.
Signed-off-by: NKangjie Lu <kjlu@umn.edu>
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/slimbus/qcom-ngd-ctrl.c

@@ -1331,6 +1331,10 @@ static int of_qcom_slim_ngd_register(struct device *parent,
 			return -ENOMEM;
 
 		ngd->pdev = platform_device_alloc(QCOM_SLIM_NGD_DRV_NAME, id);
+		if (!ngd->pdev) {
+			kfree(ngd);
+			return -ENOMEM;
+		}
 		ngd->id = id;
 		ngd->pdev->dev.parent = parent;
 		ngd->pdev->driver_override = QCOM_SLIM_NGD_DRV_NAME;