net: xilinx: emaclite: Remove xemaclite_remove_ndev()

xemaclite_remove_ndev() is a simple wrapper around free_netdev()
checking for NULL before the call. All possible paths calling
it are guaranteed to pass a non-NULL argument, so rather call
free_netdev() directly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>