9p: fix debug build error

Fixes build problem with 9p when building with debug disabled.
Also contains some fixes for warnings which pop up when 
CONFIG_NET_9P_DEBUG is disabled.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

include/net/9p/9p.h

@@ -56,9 +56,9 @@ enum p9_debug_flags {
 	P9_DEBUG_PKT =		(1<<10),
 };
 
+#ifdef CONFIG_NET_9P_DEBUG
 extern unsigned int p9_debug_level;
 
-#ifdef CONFIG_NET_9P_DEBUG
 #define P9_DPRINTK(level, format, arg...) \
 do {  \
 	if ((p9_debug_level & level) == level) {\

net/9p/protocol.c

@@ -53,6 +53,7 @@
 static int
 p9pdu_writef(struct p9_fcall *pdu, int optional, const char *fmt, ...);
 
+#ifdef CONFIG_NET_9P_DEBUG
 void
 p9pdu_dump(int way, struct p9_fcall *pdu)
 {
@@ -81,6 +82,12 @@ p9pdu_dump(int way, struct p9_fcall *pdu)
 	else
 		P9_DPRINTK(P9_DEBUG_PKT, "]]](%d) %s\n", datalen, buf);
 }
+#else
+void
+p9pdu_dump(int way, struct p9_fcall *pdu)
+{
+}
+#endif
 EXPORT_SYMBOL(p9pdu_dump);
 
 void p9stat_free(struct p9_wstat *stbuf)
@@ -542,8 +549,10 @@ int p9pdu_finalize(struct p9_fcall *pdu)
 	err = p9pdu_writef(pdu, 0, "d", size);
 	pdu->size = size;
 
+#ifdef CONFIG_NET_9P_DEBUG
 	if ((p9_debug_level & P9_DEBUG_PKT) == P9_DEBUG_PKT)
 		p9pdu_dump(0, pdu);
+#endif
 
 	P9_DPRINTK(P9_DEBUG_9P, ">>> size=%d type: %d tag: %d\n", pdu->size,
 							pdu->id, pdu->tag);

net/9p/trans_fd.c

@@ -678,11 +678,9 @@ static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
 
 static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
 {
-	struct p9_trans_fd *ts = client->trans;
-	struct p9_conn *m = ts->conn;
 	int ret = 1;
 
-	P9_DPRINTK(P9_DEBUG_TRANS, "mux %p req %p\n", m, req);
+	P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
 
 	spin_lock(&client->lock);
 	list_del(&req->req_list);