mlxsw: spectrum_flower: Remove bogus warns in mlxsw_sp_flower_destroy

This warnings may be hit even in case they should not - in case user
puts a TC-flower rule which failed to be offloaded. So just remove them.

Reported-by: Petr Machata <petrm@mellanox.com>
Reported-by: Ido Schimmel <idosch@mellanox.com>
Fixes: commit 7aa0f5aa

 ("mlxsw: spectrum: Implement TC flower offload")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>