ath6kl: change aggreation timeout message from an error to a debug message

When I connect to my Linksys WT610N AP supporting 11n I see a lot of
aggreation timeout errors:

[  408.885053] ath6kl: aggr timeout (st 3109 end 3140)
[  463.872108] ath6kl: aggr timeout (st 3671 end 3702)
[  495.010060] ath6kl: aggr timeout (st 3983 end 4014)
[  503.604047] ath6kl: aggr timeout (st 4065 end 0)
[  518.963047] ath6kl: aggr timeout (st 141 end 172)
[  525.014066] ath6kl: aggr timeout (st 205 end 236)
[  573.957051] ath6kl: aggr timeout (st 701 end 732)
[  585.019067] ath6kl: aggr timeout (st 816 end 847)

But still the connection seems to work. To not clutter the logs change
the error message to a debug message. But add a fixme comment so that
this will be investigated.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath6kl/debug.h b/drivers/net/wireless/ath/ath6kl/debug.h
index 2e60588..66b3999 100644
--- a/drivers/net/wireless/ath/ath6kl/debug.h
+++ b/drivers/net/wireless/ath/ath6kl/debug.h
@@ -35,6 +35,7 @@
 	ATH6KL_DBG_SCATTER	= BIT(12),    /* hif scatter tracing */
 	ATH6KL_DBG_WLAN_CFG     = BIT(13),    /* cfg80211 i/f file tracing */
 	ATH6KL_DBG_RAW_BYTES    = BIT(14),    /* dump tx/rx and wmi frames */
+	ATH6KL_DBG_AGGR		= BIT(15),    /* aggregation */
 	ATH6KL_DBG_ANY	        = 0xffffffff  /* enable all logs */
 };