net: tcp: Move the CLOSED state to the front

In enum tcp_state {}, the CLOSED state was put at the last one.
When we do Sequence & Ack validation, we will need to skip the
CLOSED, LISTEN, SYNSENT states. It is easier for coding if we
put the CLOSED to the front, e.g. if state > SYNSENT. And, in
other OSes, the state sequence is normally defined like this.

Signed-off-by: Shrek Wang <[email protected]>

Author: shrek-wang

subsys/net/ip/tcp_private.h

@@ -198,6 +198,7 @@ struct tcp_mss_option {
 
 enum tcp_state {
 	TCP_UNUSED = 0,
+	TCP_CLOSED,
 	TCP_LISTEN,
 	TCP_SYN_SENT,
 	TCP_SYN_RECEIVED,
@@ -207,8 +208,7 @@ enum tcp_state {
 	TCP_CLOSE_WAIT,
 	TCP_CLOSING,
 	TCP_LAST_ACK,
-	TCP_TIME_WAIT,
-	TCP_CLOSED
+	TCP_TIME_WAIT
 };
 
 enum tcp_data_mode {