[TIPC]: Remove code bloat introduced by print buffer rework

This patch allows the compiler to optimize out any code that tries to
send debugging output to the null print buffer (TIPC_NULL), a capability
that was unintentionally broken during the recent print buffer rework.
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/tipc/core.h

@@ -83,9 +83,9 @@ void tipc_dump(struct print_buf*,const char *fmt, ...);
 #define warn(fmt, arg...) tipc_printf(TIPC_OUTPUT, KERN_WARNING "TIPC: " fmt, ## arg)
 #define info(fmt, arg...) tipc_printf(TIPC_OUTPUT, KERN_NOTICE "TIPC: " fmt, ## arg)
 
-#define dbg(fmt, arg...)  do {if (DBG_OUTPUT) tipc_printf(DBG_OUTPUT, fmt, ## arg);} while(0)
-#define msg_dbg(msg, txt) do {if (DBG_OUTPUT) tipc_msg_print(DBG_OUTPUT, msg, txt);} while(0)
-#define dump(fmt, arg...) do {if (DBG_OUTPUT) tipc_dump(DBG_OUTPUT, fmt, ##arg);} while(0)
+#define dbg(fmt, arg...)  do {if (DBG_OUTPUT != TIPC_NULL) tipc_printf(DBG_OUTPUT, fmt, ## arg);} while(0)
+#define msg_dbg(msg, txt) do {if (DBG_OUTPUT != TIPC_NULL) tipc_msg_print(DBG_OUTPUT, msg, txt);} while(0)
+#define dump(fmt, arg...) do {if (DBG_OUTPUT != TIPC_NULL) tipc_dump(DBG_OUTPUT, fmt, ##arg);} while(0)
 
 
 /*	

net/tipc/link.c

@@ -132,7 +132,7 @@ static void link_print(struct link *l_ptr, struct print_buf *buf,
  * allow the output from multiple links to be intermixed.  For this reason
  * routines of the form "dbg_link_XXX()" have been created that will capture
  * debug info into a link's personal print buffer, which can then be dumped
- * into the TIPC system log (LOG) upon request.
+ * into the TIPC system log (TIPC_LOG) upon request.
  *
  * To enable per-link debugging, use LINK_LOG_BUF_SIZE to specify the size
  * of the print buffer used by each link.  If LINK_LOG_BUF_SIZE is set to 0,
@@ -141,7 +141,7 @@ static void link_print(struct link *l_ptr, struct print_buf *buf,
  * when there is only a single link in the system being debugged.
  *
  * Notes:
- * - When enabled, LINK_LOG_BUF_SIZE should be set to at least 1000 (bytes)
+ * - When enabled, LINK_LOG_BUF_SIZE should be set to at least TIPC_PB_MIN_SIZE
  * - "l_ptr" must be valid when using dbg_link_XXX() macros  
  */
 
@@ -159,13 +159,13 @@ static void link_print(struct link *l_ptr, struct print_buf *buf,
 
 static void dbg_print_link(struct link *l_ptr, const char *str)
 {
-	if (DBG_OUTPUT)
+	if (DBG_OUTPUT != TIPC_NULL)
 		link_print(l_ptr, DBG_OUTPUT, str);
 }
 
 static void dbg_print_buf_chain(struct sk_buff *root_buf)
 {
-	if (DBG_OUTPUT) {
+	if (DBG_OUTPUT != TIPC_NULL) {
 		struct sk_buff *buf = root_buf;
 
 		while (buf) {