net/rocker: Remove unreachable return instruction

The "return 0" instruction follows other return instruction
and it makes it impossible to execute, hence remove it.

Fixes: 00fc0c51 ("rocker: Change world_ops API and implementation to be switchdev independant")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>