ath9k: Return early for invalid rates

Process and update the internal RSSI average, which
is used by ANI, after verifying that the received
frame has valid rate information.

Signed-off-by: Sujith Manoharan <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/ath/ath9k/recv.c

···
 	if (rx_stats->rs_more)
 		return 0;
 
-	ath9k_process_rssi(common, hw, hdr, rx_stats);
-
 	if (ath9k_process_rate(common, hw, rx_stats, rx_status))
 		return -EINVAL;
+
+	ath9k_process_rssi(common, hw, hdr, rx_stats);
 
 	rx_status->band = hw->conf.chandef.chan->band;
 	rx_status->freq = hw->conf.chandef.chan->center_freq;