cfg80211: fix compilation warning for cfg80211_leave_all()

The following compilation issue popped up moving from v3.10-rc1 to
v3.10-rc6 after merging wireless-testing.

net/wireless/sysfs.c:86:13: error: 'cfg80211_leave_all' defined
but not used [-Werror=unused-function]

The function is only called when CONFIG_PM is enabled. Moving the
function under CONFIG_PM as well.
Signed-off-by: NArend van Spriel <arend@broadcom.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

net/wireless/sysfs.c

@@ -83,6 +83,7 @@ static int wiphy_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
+#ifdef CONFIG_PM
 static void cfg80211_leave_all(struct cfg80211_registered_device *rdev)
 {
 	struct wireless_dev *wdev;
@@ -91,7 +92,6 @@ static void cfg80211_leave_all(struct cfg80211_registered_device *rdev)
 		cfg80211_leave(rdev, wdev);
 }
 
-#ifdef CONFIG_PM
 static int wiphy_suspend(struct device *dev, pm_message_t state)
 {
 	struct cfg80211_registered_device *rdev = dev_to_rdev(dev);