If we try to stop a scheduled scan while it is not running, we should
return -ENOENT instead of simply ignoring the command and returning
success.  This is more consistent with other parts of the code.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
  *     passed, all channels allowed for the current regulatory domain
  *     are used.  Extra IEs can also be passed from the userspace by
  *     using the %NL80211_ATTR_IE attribute.
- * @NL80211_CMD_STOP_SCHED_SCAN: stop a scheduled scan
+ * @NL80211_CMD_STOP_SCHED_SCAN: stop a scheduled scan.  Returns -ENOENT
+ *     if scheduled scan is not running.
  * @NL80211_CMD_SCHED_SCAN_RESULTS: indicates that there are scheduled scan
  *     results available.
  * @NL80211_CMD_SCHED_SCAN_STOPPED: indicates that the scheduled scan has
 
        ASSERT_RDEV_LOCK(rdev);
 
        if (!rdev->sched_scan_req)
-               return 0;
+               return -ENOENT;
 
        dev = rdev->sched_scan_req->dev;