net: dsa: rtl8366rb: Support all 4096 VLANs

[ Upstream commit a7920efdd86d8a0d74402dbc80ead03b023294ba ]

There is an off-by-one error in rtl8366rb_is_vlan_valid()
making VLANs 0..4094 valid while it should be 1..4095.
Fix it.

Fixes: d8652956cf37 ("net: dsa: realtek-smi: Add Realtek SMI driver")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
diff --git a/drivers/net/dsa/rtl8366rb.c b/drivers/net/dsa/rtl8366rb.c
index f4b14b6..5aefd7a 100644
--- a/drivers/net/dsa/rtl8366rb.c
+++ b/drivers/net/dsa/rtl8366rb.c
@@ -1270,7 +1270,7 @@
 	if (smi->vlan4k_enabled)
 		max = RTL8366RB_NUM_VIDS - 1;
 
-	if (vlan == 0 || vlan >= max)
+	if (vlan == 0 || vlan > max)
 		return false;
 
 	return true;