l2tp: correct debugfs label for tunnel tx stats

l2tp_dfs_seq_tunnel_show prints two groups of tunnel statistics. The
first group reports transmit counters, but the code labels it as rx.
Set the label to "tx" so the debugfs output reflects the actual meaning.

Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20251128085300.3377210-1-alok.a.tiwari@oracle.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: aloktiwa

net/l2tp/l2tp_debugfs.c

@@ -163,7 +163,7 @@ static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
 	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
 		   tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
 		   refcount_read(&tunnel->ref_count));
-	seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
+	seq_printf(m, " %08x tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
 		   0,
 		   atomic_long_read(&tunnel->stats.tx_packets),
 		   atomic_long_read(&tunnel->stats.tx_bytes),