usb: typec: qcom: fix return value check in qcom_pmic_typec_probe()

device_get_named_child_node() returns NULL, if it fails, replace
IS_ERR() with NULL pointer check.

Fixes: a4422ff2 ("usb: typec: qcom: Add Qualcomm PMIC Type-C driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Acked-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230725125319.565733-1-yangyingliang@huawei.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>