soc: qcom: rpmpd: Check for null return of devm_kcalloc

Because of the possible failure of the allocation, data->domains might
be NULL pointer and will cause the dereference of the NULL pointer
later.
Therefore, it might be better to check it and directly return -ENOMEM
without releasing data manually if fails, because the comment of the
devm_kmalloc() says "Memory allocated with this function is
automatically freed on driver detach.".

Fixes: bbe3a66c3f5a ("soc: qcom: rpmpd: Add a Power domain driver to model corners")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20211231094419.1941054-1-jiasheng@iscas.ac.cn

drivers/soc/qcom/rpmpd.c

@@ -610,6 +610,9 @@ static int rpmpd_probe(struct platform_device *pdev)
 
 	data->domains = devm_kcalloc(&pdev->dev, num, sizeof(*data->domains),
 				     GFP_KERNEL);
+	if (!data->domains)
+		return -ENOMEM;
+
 	data->num_domains = num;
 
 	for (i = 0; i < num; i++) {