task #28910367
Rather than explicitly specifying "-o
default_permissions,allow_other", virtiofs can set some default values
for them.

With this, we can simply do
"mount -t virtio_fs atest /mnt/test/ -otag=myfs-1,dax".
Signed-off-by: NLiu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>