ath10k: split an unnecessary long line

from checkpatch:

drivers/net/wireless/ath/ath10k/mac.c:1113: line over 90 characters
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/mac.c

@@ -1110,7 +1110,8 @@ static int ath10k_monitor_recalc(struct ath10k *ar)
 
 			ret = ath10k_monitor_stop(ar);
 			if (ret)
-				ath10k_warn(ar, "failed to stop disallowed monitor: %d\n", ret);
+				ath10k_warn(ar, "failed to stop disallowed monitor: %d\n",
+					    ret);
 				/* not serious */
 		}