regulator: fp9931: Add missing memory allocation check

Add a check for devm_kzalloc failure in fp9931_probe to prevent a
null pointer dereference.

Fixes: 12d821b ("regulator: Add FP9931/JD9930 driver")
Signed-off-by: Felix Gu <gu_0233@qq.com>
Link: https://patch.msgid.link/tencent_5FCF2108621C51007E5526A7C60A5CC1F306@qq.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: Felix Gu

drivers/regulator/fp9931.c

@@ -439,6 +439,9 @@ static int fp9931_probe(struct i2c_client *client)
 	int i;
 
 	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
 	data->regmap = devm_regmap_init_i2c(client, &regmap_config);
 	if (IS_ERR(data->regmap))
 		return dev_err_probe(&client->dev, PTR_ERR(data->regmap),