net: mvneta: Don't check NETIF_F_GRO ourself

napi_gro_receive() checks NETIF_F_GRO bit as well, if the bit is not
set, we will go through GRO_NORMAL in napi_skb_finish(), so fall back
to netif_receive_skb_internal(), so we don't need to check NETIF_F_GRO
ourself.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Gregory CLEMENT <gregory.clement@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>