ia64: csum_partial_copy_nocheck(): don't abuse csum_partial_copy_from_user()

Just inline the call and use memcpy() instead of __copy_from_user() and
note that the tail is precisely ia64 csum_partial().
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/ia64/lib/csum_partial_copy.c

@@ -134,8 +134,8 @@ EXPORT_SYMBOL(csum_partial_copy_from_user);
 __wsum
 csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
 {
-	return csum_partial_copy_from_user((__force const void __user *)src,
-					   dst, len, sum, NULL);
+	memcpy(dst, src, len);
+	return csum_partial(dst, len, sum);
 }
 
 EXPORT_SYMBOL(csum_partial_copy_nocheck);