ath5k: Introduce _ath5k_printk to reduce code/text

Macros can be converted to functions to reduce overall object size.

Convert the ATH5K_PRINTK macro to use _ath5k_printk.

Allyesconfig size is reduced ~10%

$ size drivers/net/wireless/ath/ath5k/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 211557	   2032	  40672	 254261	  3e135	drivers/net/wireless/ath/ath5k/built-in.o.new
 235412	   2032	  47296	 284740	  45844	drivers/net/wireless/ath/ath5k/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
index a9c0503..3007bba 100644
--- a/drivers/net/wireless/ath/ath5k/base.c
+++ b/drivers/net/wireless/ath/ath5k/base.c
@@ -3040,3 +3040,23 @@
 	ath5k_hw_set_rx_filter(ah, rfilt);
 	ah->filter_flags = rfilt;
 }
+
+void _ath5k_printk(const struct ath5k_hw *ah, const char *level,
+		   const char *fmt, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, fmt);
+
+	vaf.fmt = fmt;
+	vaf.va = &args;
+
+	if (ah && ah->hw)
+		printk("%s" pr_fmt("%s: %pV"),
+		       level, wiphy_name(ah->hw->wiphy), &vaf);
+	else
+		printk("%s" pr_fmt("%pV"), level, &vaf);
+
+	va_end(args);
+}