replmd: Get rid of duplicated replmd_build_la_val() code

replmd: Get rid of duplicated replmd_build_la_val() code

replmd_build_la_val() and replmd_set_la_val() are pretty much identical.
Keep the replmd_build_la_val() API (as it makes it clearer we're
creating a new linked attribute), but replace the code with a call to
replmd_set_la_val().

This isn't required for any bug fix, but is just a general tidy-up to
avoid code duplication.

Signed-off-by: Tim Beale <timbeale@catalyst.net.nz>
Reviewed-by: Garming Sam <garming@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>