docs: orangefs: fix pvfs2tab literal block

Following a merge fix-up, the literal block is introduced too early;
this patch merges the localhost mention with the introduction, fixing

	Documentation/filesystems/orangefs.rst:124: WARNING: Literal block expected; none found.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Link: https://lore.kernel.org/r/20200424153515.134500-1-steve@sk2.org


Signed-off-by: Jonathan Corbet <corbet@lwn.net>