sfc: fix an off by one bug

This bug is harmless because it's just a sanity check and we always
pass valid values for "encap_type" but the test is off by one.

Fixes: 9b4108012517 ("sfc: insert catch-all filters for encapsulated traffic")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/sfc/ef10.c

@@ -5134,7 +5134,7 @@ static int efx_ef10_filter_insert_def(struct efx_nic *efx,
 
 		/* quick bounds check (BCAST result impossible) */
 		BUILD_BUG_ON(EFX_EF10_BCAST != 0);
-		if (encap_type > ARRAY_SIZE(map) || map[encap_type] == 0) {
+		if (encap_type >= ARRAY_SIZE(map) || map[encap_type] == 0) {
 			WARN_ON(1);
 			return -EINVAL;
 		}