[IPv6]: Only modify checksum for UDP

Only change upper-layer checksum from 0 to 0xFFFF for UDP (as RFC 768
states), not for others as RFC 4443 doesn't require it.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed