mac80211_hwsim: Fix set mactime on receiver hwsim radio

The patch "mac80211_hwsim:  Add tsf to beacons, probe responses and radiotap
header" was setting the mactime on wrong hwsim radio. This patch fixes it.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>