[PATCH] uml: remove duplicate export

The export is together with the definition, in arch/x86_64/lib/csum-partial.c,
which is compiled in by arch/um/sys-x86_64/Makefile.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>