[PATCH] lan78xx: Protect runtime_auto check by #ifdef CONFIG_PM

[Geert Uytterhoeven <geert@linux-m68k.org>]

If CONFIG_PM=n:

    drivers/net/usb/lan78xx.c: In function ‘lan78xx_get_stats64’:
    drivers/net/usb/lan78xx.c:3274: error: ‘struct dev_pm_info’ has no member named ‘runtime_auto’

If PM is disabled, the runtime_auto flag is not available, but auto
suspend is not enabled anyway.  Hence protect the check for runtime_auto
by #ifdef CONFIG_PM to fix this.

Fixes: a59f8c5b048dc938 ("lan78xx: add ndo_get_stats64")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
Alternatively, we can add a dev_pm_runtime_auto_is_enabled() wrapper to
include/linux/pm.h, which always return false if CONFIG_PM is disabled.

The only other user in non-core code (drivers/usb/core/sysfs.c) has a
big #ifdef CONFIG_PM check around all PM-related code.

Thoughts?
---
 drivers/net/usb/lan78xx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/usb/lan78xx.c b/drivers/net/usb/lan78xx.c
index d36d5ebf37f355f2..7b9ac47b2ecf9905 100644
--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -3271,7 +3271,9 @@ struct rtnl_link_stats64 *lan78xx_get_stats64(struct net_device *netdev,
 	 * periodic reading from HW will prevent from entering USB auto suspend.
 	 * if autosuspend is disabled, read from HW.
 	 */
+#ifdef CONFIG_PM
 	if (!dev->udev->dev.power.runtime_auto)
+#endif
 		lan78xx_update_stats(dev);
 
 	mutex_lock(&dev->stats.access_lock);
-- 
1.9.1