ath9k: Add wiphy name to log messages.

On systems with multiple NICs, it's nice to know which
one is producing warnings.  Here is an example of the
new ouput:

ath: wiphy0: Failed to stop TX DMA, queues=0x005!

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/main.c b/drivers/net/wireless/ath/main.c
index d9218fe..ea2c737 100644
--- a/drivers/net/wireless/ath/main.c
+++ b/drivers/net/wireless/ath/main.c
@@ -57,7 +57,8 @@
 }
 EXPORT_SYMBOL(ath_rxbuf_alloc);
 
-void ath_printk(const char *level, const char *fmt, ...)
+void ath_printk(const char *level, const struct ath_common* common,
+		const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;
@@ -67,7 +68,11 @@
 	vaf.fmt = fmt;
 	vaf.va = &args;
 
-	printk("%sath: %pV", level, &vaf);
+	if (common && common->hw && common->hw->wiphy)
+		printk("%sath: %s: %pV",
+		       level, wiphy_name(common->hw->wiphy), &vaf);
+	else
+		printk("%sath: %pV", level, &vaf);
 
 	va_end(args);
 }