ath: Fix smatch warning

drivers/net/wireless/ath/main.c:88 ath_printk()
	 error: we previously assumed 'common->hw' could be null (see line 82)

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/main.c

@@ -79,13 +79,13 @@ void ath_printk(const char *level, const struct ath_common* common,
 	vaf.fmt = fmt;
 	vaf.va = &args;
 
-	if (common && common->hw && common->hw->wiphy)
+	if (common && common->hw && common->hw->wiphy) {
 		printk("%sath: %s: %pV",
 		       level, wiphy_name(common->hw->wiphy), &vaf);
-	else
+		trace_ath_log(common->hw->wiphy, &vaf);
+	} else {
 		printk("%sath: %pV", level, &vaf);
-
-	trace_ath_log(common->hw->wiphy, &vaf);
+	}
 
 	va_end(args);
 }