tcp: increase LINUX_MIB_BEYOND_WINDOW for SKB_DROP_REASON_TCP_OVERWINDOW

tcp: increase LINUX_MIB_BEYOND_WINDOW for SKB_DROP_REASON_TCP_OVERWINDOW

Since commit 9ca48d616ed7 ("tcp: do not accept packets beyond
window"), the path leading to SKB_DROP_REASON_TCP_OVERWINDOW in
tcp_data_queue() is probably dead. However, it can be reached now when
tcp_max_receive_window() is larger than tcp_receive_window(). In that
case, increment LINUX_MIB_BEYOND_WINDOW as done in tcp_sequence().

Signed-off-by: Simon Baatz <gmbnomis@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260309-tcp_rfc7323_retract_wnd_rfc-v3-3-4c7f96b1ec69@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>