[DCCP]: enable debug messages also for static builds

This patch
  * makes debugging (when configured) work both for static / module build
  * provides generic debugging macros for use in other DCCP / CCID modules
  * adds missing information about debug parameters to Kconfig
  * performs some code tidy-up

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
diff --git a/net/dccp/Kconfig b/net/dccp/Kconfig
index 2fc5e55..b8a68dd 100644
--- a/net/dccp/Kconfig
+++ b/net/dccp/Kconfig
@@ -38,6 +38,9 @@
 	---help---
 	  Only use this if you're hacking DCCP.
 
+	  When compiling DCCP as a module, this debugging output can be toggled
+	  by setting the parameter dccp_debug of the `dccp' module to 0 or 1.
+
 	  Just say N.
 
 config NET_DCCPPROBE