mac80211: Use ktime_get_ts()

do_posix_clock_monotonic_gettime() is a leftover from the initial
posix timer implementation which maps to ktime_get_ts().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c
index ee82e1f..3db96648 100644
--- a/net/mac80211/debugfs_sta.c
+++ b/net/mac80211/debugfs_sta.c
@@ -124,7 +124,7 @@
 	long connected_time_secs;
 	char buf[100];
 	int res;
-	do_posix_clock_monotonic_gettime(&uptime);
+	ktime_get_ts(&uptime);
 	connected_time_secs = uptime.tv_sec - sta->last_connected;
 	time_to_tm(connected_time_secs, 0, &result);
 	result.tm_year -= 70;