iwlegacy: 4965-rs: remove null check on sta in il4965_rs_tx_status

the null check on sta in il4965_rs_tx_status is not necessary
Signed-off-by: Greg Dietsche <Gregory.Dietsche@cuw.edu>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>

drivers/net/wireless/iwlegacy/4965-rs.c

@@ -991,7 +991,7 @@ il4965_rs_tx_status(void *il_r, struct ieee80211_supported_band *sband,
 	lq_sta->last_rate_n_flags = tx_rate;
 done:
 	/* See if there's a better rate or modulation mode to try. */
-	if (sta && sta->supp_rates[sband->band])
+	if (sta->supp_rates[sband->band])
 		il4965_rs_rate_scale_perform(il, skb, sta, lq_sta);
 }