*/*: Fix wpa_supplicant* and hostapd* EAPOL_TEST build

Fix EAPOL_TEST build. Local funcion os_fdatasync() is valid under
FreeBSD as fdatasync(2) is supported.

PR: 261636
Reported by: David Siebörger <drs-freebsd@sieborger.nom.za>

(cherry picked from commit 74e181d200eeb192160951934cd3b16014682d8c)