libsmb: Fix parsing symlink reparse points

libsmb: Fix parsing symlink reparse points

Untested code is broken code. For symlinks we need to hand over the
full reparse buffer into symlink_reparse_buffer_parse(), as this is
also used for the smb2 error response handling. For that, the
"reserved" field in [MS-FSCC] 2.1.2.4 Symbolic Link Reparse Data
Buffer is used for the "unparsed" field.

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Fri Sep  8 17:24:19 UTC 2023 on atb-devel-224