mlxsw: spectrum_buffers: Use MLXSW_SP_PB_UNUSED define for unused pb

Suggested-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed