9p: Make transports dynamic

This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules.  This should also allow kernel
configuration of transports without ifdef-hell.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/client.c b/net/9p/client.c
index cb17075..e161012 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -38,7 +38,7 @@
 static void p9_fid_destroy(struct p9_fid *fid);
 static struct p9_stat *p9_clone_stat(struct p9_stat *st, int dotu);
 
-struct p9_client *p9_client_create(struct p9_transport *trans, int msize,
+struct p9_client *p9_client_create(struct p9_trans *trans, int msize,
 								   int dotu)
 {
 	int err, n;