The vfs_*_feature() macros turn anything that uses them into dead code,
so we can delete all of it.
As a side effect, zfs_set_fuid_feature() is now identical in
module/os/freebsd/zfs/zfs_vnops_os.c and
module/os/linux/zfs/zfs_vnops_os.c. A few other functions are identical
too. Future cleanup could move these into a common file.
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes#13832