rc80211-pid: export human-readable target_pf value to debugfs

Export the non-shifted target_pf value to debugfs, so that it's human-readable.

Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/mac80211/rc80211_pid_algo.c b/net/mac80211/rc80211_pid_algo.c
index 631e468..b84e514 100644
--- a/net/mac80211/rc80211_pid_algo.c
+++ b/net/mac80211/rc80211_pid_algo.c
@@ -210,7 +210,7 @@
 	rate_control_pid_normalize(pinfo, mode->num_rates);
 
 	/* Compute the proportional, integral and derivative errors. */
-	err_prop = pinfo->target - pf;
+	err_prop = (pinfo->target << RC_PID_ARITH_SHIFT) - pf;
 
 	err_avg = spinfo->err_avg_sc >> pinfo->smoothing_shift;
 	spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop;