tcp: move mtu_info to remove two 32bit holes

This removes 8bytes waste on 64bit builds.

Signed-off-by: Eric Dumazet <[email protected]>
Reviewed-by: Kuniyuki Iwashima <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: edumazet

include/linux/tcp.h

@@ -448,6 +448,9 @@ struct tcp_sock {
 				 * the first SYN. */
 	u32	undo_marker;	/* snd_una upon a new recovery episode. */
 	int	undo_retrans;	/* number of undoable retransmissions. */
+	u32	mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
+			   * while socket was owned by user.
+			   */
 	u64	bytes_retrans;	/* RFC4898 tcpEStatsPerfOctetsRetrans
 				 * Total data bytes retransmitted
 				 */
@@ -494,9 +497,6 @@ struct tcp_sock {
 		u32		  probe_seq_end;
 	} mtu_probe;
 	u32     plb_rehash;     /* PLB-triggered rehash attempts */
-	u32	mtu_info; /* We received an ICMP_FRAG_NEEDED / ICMPV6_PKT_TOOBIG
-			   * while socket was owned by user.
-			   */
 #if IS_ENABLED(CONFIG_MPTCP)
 	bool	is_mptcp;
 #endif