Revision 217608

MFC r217481 and r217606 from /head

r217481...
  Fix the mount example of xfs(5) filesystems by including the read-only
  option.  We only support ro mounts for xfs, so it’s nice if the examples
  we show in the manpage are easy to copy/paste.

  PR:           docs/149106
  Submitted by: amdmi3

r217606...
  Bump .Dd date of manpage for r217481