Bluetooth: Move more channel info to struct l2cap_chan

In this commit, omtu, imtu, flush_to, mode and sport. It also remove the
pi var from l2cap_sock_sendmsg().

Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>
diff --git a/net/bluetooth/cmtp/core.c b/net/bluetooth/cmtp/core.c
index cce99b0..c5b11af 100644
--- a/net/bluetooth/cmtp/core.c
+++ b/net/bluetooth/cmtp/core.c
@@ -346,7 +346,8 @@
 
 	bacpy(&session->bdaddr, &bt_sk(sock->sk)->dst);
 
-	session->mtu = min_t(uint, l2cap_pi(sock->sk)->omtu, l2cap_pi(sock->sk)->imtu);
+	session->mtu = min_t(uint, l2cap_pi(sock->sk)->chan->omtu,
+					l2cap_pi(sock->sk)->chan->imtu);
 
 	BT_DBG("mtu %d", session->mtu);