phy: qcom: phy-qcom-m31: fix wrong pointer pass to PTR_ERR()

It should be 'qphy->vreg' passed to PTR_ERR() when devm_regulator_get() fails.

Fixes: 08e49af5

 ("phy: qcom: Introduce M31 USB PHY driver")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Link: https://lore.kernel.org/r/20230824091345.1072650-1-yangyingliang@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>