net/9p: Use virtio transpart as the default transport

Make the default 9p experience better by defaulting to virtio transport if present.
These days most of the users are using 9p in a virtualized setup

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/net/9p/client.c b/net/9p/client.c
index 812a4cd..5e94dab 100644
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1015,6 +1015,9 @@
 		goto destroy_tagpool;
 
 	if (!clnt->trans_mod)
+		clnt->trans_mod = v9fs_get_trans_by_name("virtio");
+
+	if (!clnt->trans_mod)
 		clnt->trans_mod = v9fs_get_default_trans();
 
 	if (clnt->trans_mod == NULL) {