backlight: qcom-wled: Pass number of elements to read to read_u32_array

of_property_read_u32_array takes the number of elements to read as last
argument. This does not always need to be 4 (sizeof(u32)) but should
instead be the size of the array in DT as read just above with
of_property_count_elems_of_size.

To not make such an error go unnoticed again the driver now bails
accordingly when of_property_read_u32_array returns an error.
Surprisingly the indentation of newlined arguments is lining up again
after prepending `rc = `.

Fixes: 775d2ffb4a ("backlight: qcom-wled: Restructure the driver for WLED3")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20211115203459.1634079-3-marijn.suijten@somainline.org

drivers/video/backlight/qcom-wled.c

@@ -1535,10 +1535,15 @@ static int wled_configure(struct wled *wled)
 			return -EINVAL;
 		}
 
-		of_property_read_u32_array(dev->of_node,
+		rc = of_property_read_u32_array(dev->of_node,
 						"qcom,enabled-strings",
 						wled->cfg.enabled_strings,
-						sizeof(u32));
+						string_len);
+		if (rc) {
+			dev_err(dev, "Failed to read %d elements from qcom,enabled-strings: %d\n",
+				string_len, rc);
+			return rc;
+		}
 
 		for (i = 0; i < string_len; ++i) {
 			if (wled->cfg.enabled_strings[i] >= wled->max_string_count) {