Allow linking with mold / fix the version script (#814)

Allow linking with mold / fix the version script (#814)

This fixes issue https://github.com/libfuse/libfuse/issues/810
and should avoid mold linking errors.
Commit d4e294b removed made fuse_register_module() a static
function, but forgot to remove it from the version script.

Commit fe4f942 introduced copy_file_range to libfuse and
added the non-exiting (neither declared nor defined) function
fuse_reply_copy_file_range() to the version script. Kernel
side just exects an integer reply how much was copied, using
fuse_reply_write() as in fuse_lib_copy_file_range() is sufficient
and no extra function is needed.

Co-authored-by: Bernd Schubert <bschubert@ddn.com>