net/samba419: Use a simple approach to reconcile O_PATH and vfs_zfsacl

The current, sophisticated approach does not fully cover all usecases and flag
twiddling around O_EMPTY_PATH, resort to use working fdescfs(5) magic for now.

PR: 277878
Tested by: michaelo, vvd, Peter Eriksson
Approved by: jrm (mentor), vvd, mikael (samba)
MFH: 2025Q1
Differential Revision: https://reviews.freebsd.org/D48399