net: dsa: mv88e6xxx: Fix off-by-one in VTU devlink region size

In the unlikely event of the VTU being loaded to the brim with 4k
entries, the last one was placed in the buffer, but the size reported
to devlink was off-by-one. Make sure that the final entry is available
to the caller.

Fixes: ca4d632a ("net: dsa: mv88e6xxx: Export VTU as devlink region")
Signed-off-by: Tobias Waldekranz <tobias@waldekranz.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mv88e6xxx/devlink.c

@@ -678,7 +678,7 @@ static int mv88e6xxx_setup_devlink_regions_global(struct dsa_switch *ds,
 				sizeof(struct mv88e6xxx_devlink_atu_entry);
 			break;
 		case MV88E6XXX_REGION_VTU:
-			size = mv88e6xxx_max_vid(chip) *
+			size = (mv88e6xxx_max_vid(chip) + 1) *
 				sizeof(struct mv88e6xxx_devlink_vtu_entry);
 			break;
 		}