CC [M]  net/mac80211/rc80211_pid_algo.o
net/mac80211/rc80211_pid_algo.c: In function ‘rate_control_pid_rate_init’:
net/mac80211/rc80211_pid_algo.c:304: warning: unused variable ‘si’
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>