usb: common: usb-conn-gpio: Don't log an error on probe deferral

This patch makes the printout of the error message for failing to get a
VBUS regulator handle conditional on the error code being something other
than -EPROBE_DEFER.

Deferral is a normal thing, we don't need an error message for this.

Cc: Chunfeng Yun <chunfeng.yun@mediatek.com>
Cc: Nagarjuna Kristam <nkristam@nvidia.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191128134358.3880498-2-bryan.odonoghue@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/common/usb-conn-gpio.c

@@ -156,7 +156,8 @@ static int usb_conn_probe(struct platform_device *pdev)
 
 	info->vbus = devm_regulator_get(dev, "vbus");
 	if (IS_ERR(info->vbus)) {
-		dev_err(dev, "failed to get vbus\n");
+		if (PTR_ERR(info->vbus) != -EPROBE_DEFER)
+			dev_err(dev, "failed to get vbus\n");
 		return PTR_ERR(info->vbus);
 	}