RDMA/irdma: Cleanup and rename irdma_netdev_vlan_ipv6()

The return value from irdma_netdev_vlan_ipv6() is not used. Rename
the functions and change to a void return.

Signed-off-by: Mustafa Ismail <mustafa.ismail@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Link: https://lore.kernel.org/r/20230725155505.1069-5-shiraz.saleem@intel.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>