Re-fix -Wwrite-strings on FreeBSD
Follow up fix for a926aab902ac5c680f4766568d19674b80fb58bb.
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #13348
Closes #13610