fix endian lossage in forcedeth

a) if you initialize something with le32_to_cpu(...), then |= it
with host-endian and feed to cpu_to_le32(), it's most definitely
*not* __le32.  As sparse would've told you...

b) the whole sequence is |= cpu_to_le32(host-endian constant)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>