usbip: vhci_hcd indicate failed message

If the return value of vhci_init_attr_group and
sysfs_create_group is non-zero, which mean they failed
to init attr_group and create sysfs group, so it would
better add 'failed' message to indicate that.
This patch also change pr_err to dev_err to trace which
device is failed.

Fixes: 0775a9cb ("usbip: vhci extension: modifications to vhci driver")
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/r/20190916150921.152977-1-maowenan@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/usbip/vhci_hcd.c

@@ -1195,12 +1195,12 @@ static int vhci_start(struct usb_hcd *hcd)
 	if (id == 0 && usb_hcd_is_primary_hcd(hcd)) {
 		err = vhci_init_attr_group();
 		if (err) {
-			pr_err("init attr group\n");
+			dev_err(hcd_dev(hcd), "init attr group failed, err = %d\n", err);
 			return err;
 		}
 		err = sysfs_create_group(&hcd_dev(hcd)->kobj, &vhci_attr_group);
 		if (err) {
-			pr_err("create sysfs files\n");
+			dev_err(hcd_dev(hcd), "create sysfs files failed, err = %d\n", err);
 			vhci_finish_attr_group();
 			return err;
 		}