[NET] gso: Fix GSO feature mask in sk_setup_caps

This isn't a bug just yet as only TCP uses sk_setup_caps for GSO.
However, if and when UDP or something else starts using it this is
likely to cause a problem if we forget to add software emulation
for it at the same time.

The problem is that right now we translate GSO emulation to the
bitmask NETIF_F_GSO_MASK, which includes every protocol, even
ones that we cannot emulate.

This patch makes it provide only the ones that we can emulate.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/sock.c b/net/core/sock.c
index 7e51d3a..c14ce01 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -998,7 +998,7 @@
 	__sk_dst_set(sk, dst);
 	sk->sk_route_caps = dst->dev->features;
 	if (sk->sk_route_caps & NETIF_F_GSO)
-		sk->sk_route_caps |= NETIF_F_GSO_MASK;
+		sk->sk_route_caps |= NETIF_F_GSO_SOFTWARE;
 	if (sk_can_gso(sk)) {
 		if (dst->header_len)
 			sk->sk_route_caps &= ~NETIF_F_GSO_MASK;