Checksum handling largely depends on the subarch.

Thus, I renamed i386 arch_csum_partial in arch/um/sys-i386/checksum.S back to
csum_partial, removed csum_partial from arch/um/kernel/checksum.c and shifted
EXPORT_SYMBOL(csum_partial) to arch/um/sys-i386/ksyms.c.

Then, csum_partial_copy_to and csum_partial_copy_from were shifted from
arch/um/kernel/checksum.c to arch/um/include/sysdep-i386/checksum.h and
inserted in the calling functions csum_partial_copy_from_user() and
csum_and_copy_to_user().

Now, arch/um/kernel/checksum.c is empty and removed.
Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>