[PATCH] kill eth_io_copy_and_sum()

On all targets that sucker boils down to memcpy_fromio(sbk->data, from, len).
The function name is highly misguiding (it _never_ does any checksums), the
last argument is just a noise and simply expanding the call to memcpy_fromio()
gives shorter and more readable source.  For a lot of reasons it has almost
no remaining users, so it's better to just outright kill it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>