lapb: Neaten debugging

Enable dynamic debugging and remove a bunch of #ifdef/#endifs.

Add a lapb_dbg(level, fmt, ...) macro and replace the
printk(KERN_DEBUG uses.
Add pr_fmt and remove embedded prefixes.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/lapb.h b/include/net/lapb.h
index fd2bf57..df892a9 100644
--- a/include/net/lapb.h
+++ b/include/net/lapb.h
@@ -149,4 +149,10 @@
  */
 #define	LAPB_DEBUG	0
 
+#define lapb_dbg(level, fmt, ...)			\
+do {							\
+	if (level < LAPB_DEBUG)				\
+		pr_debug(fmt, ##__VA_ARGS__);		\
+} while (0)
+
 #endif