Paul's patch to fix checksum folding, commit b492f7e4 ("powerpc/64:
Fix checksum folding in csum_tcpudp_nofold and ip_fast_csum_nofold")
missed a case in csum_add(). Fix it.
Signed-off-by: NShile Zhang <shile.zhang@nokia.com>
Acked-by: NPaul Mackerras <paulus@ozlabs.org>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>