mptcp: mptcp_parse_option is no longer exported

Options parsing in now done from mptcp_incoming_options().

mptcp_parse_option() has been removed from mptcp.h when CONFIG_MPTCP is
defined but not when it is not.

Fixes: cfde141 ("mptcp: move option parsing into mptcp_incoming_options()")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/mptcp.h

@@ -217,12 +217,6 @@ static inline bool rsk_drop_req(const struct request_sock *req)
 	return false;
 }
 
-static inline void mptcp_parse_option(const struct sk_buff *skb,
-				      const unsigned char *ptr, int opsize,
-				      struct tcp_options_received *opt_rx)
-{
-}
-
 static inline bool mptcp_syn_options(struct sock *sk, const struct sk_buff *skb,
 				     unsigned int *size,
 				     struct mptcp_out_options *opts)