mlxsw: spectrum_router: Drop unnecessary parameter

Functions that take as argument a FIB entry don't need to take FIB node
as well, as it can be extracted from the entry.

Remove unnecessary FIB node parameter.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>