Fix build warnings reported by CI:

  CC      net/mptcp/protocol.o
net/mptcp/protocol.c:1430:14: warning: no previous prototype for ‘mptcp_subflow_get_send’ [-Wmissing-prototypes]
 struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk)
              ^~~~~~~~~~~~~~~~~~~~~~
net/mptcp/protocol.c:2213:14: warning: no previous prototype for ‘mptcp_subflow_get_retrans’ [-Wmissing-prototypes]
 struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk)
              ^~~~~~~~~~~~~~~~~~~~~~~~~
  CHECK   net/mptcp/protocol.c
net/mptcp/protocol.c:1430:13: warning: symbol 'mptcp_subflow_get_send' was not declared. Should it be static?
net/mptcp/protocol.c:2213:13: warning: symbol 'mptcp_subflow_get_retrans' was not declared. Should it be static?

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 net/mptcp/protocol.h | 2 ++
 net/mptcp/sched.c    | 2 --
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index fc5dca44470c..8e0ee891c423 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -629,6 +629,8 @@ void mptcp_unregister_scheduler(struct mptcp_sched_ops *sched);
 int mptcp_init_sched(struct mptcp_sock *msk,
 		     struct mptcp_sched_ops *sched);
 void mptcp_release_sched(struct mptcp_sock *msk);
+struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
+struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
 struct sock *mptcp_sched_get_send(struct mptcp_sock *msk);
 struct sock *mptcp_sched_get_retrans(struct mptcp_sock *msk);
 
diff --git a/net/mptcp/sched.c b/net/mptcp/sched.c
index 7a5654132ed3..3ceb721e6489 100644
--- a/net/mptcp/sched.c
+++ b/net/mptcp/sched.c
@@ -15,8 +15,6 @@
 
 static DEFINE_SPINLOCK(mptcp_sched_list_lock);
 static LIST_HEAD(mptcp_sched_list);
-struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk);
-struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk);
 
 /* Must be called with rcu read lock held */
 struct mptcp_sched_ops *mptcp_sched_find(const char *name)
-- 
2.34.1