backlight: pm8941: Add NULL check in wled_configure()

devm_kasprintf() returns NULL when memory allocation fails. Currently,
wled_configure() does not check for this case, which results in a NULL
pointer dereference.

Add NULL check after devm_kasprintf() to prevent this issue.

Fixes: f86b77583d88 ("backlight: pm8941: Convert to using %pOFn instead of device_node.name")
Signed-off-by: Henry Martin <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Reviewed-by: "Daniel Thompson (RISCstar)" <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lee Jones <[e-mail]>

drivers/video/backlight/qcom-wled.c

···
 	wled->ctrl_addr = be32_to_cpu(*prop_addr);
 
 	rc = of_property_read_string(dev->of_node, "label", &wled->name);
-	if (rc)
+	if (rc) {
 		wled->name = devm_kasprintf(dev, GFP_KERNEL, "%pOFn", dev->of_node);
-
+		if (!wled->name)
+			return -ENOMEM;
+	}
 	switch (wled->version) {
 	case 3:
 		u32_opts = wled3_opts;