ath: Add and use pr_fmt, convert printks to pr_<level>

Use a more current logging style.
Make sure all output is prefixed appropriately.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/desc.c

@@ -21,6 +21,8 @@
  Hardware Descriptor Functions
 \******************************/
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include "ath5k.h"
 #include "reg.h"
 #include "debug.h"