Fix POD errors in fileserver and dasalvager

Fix POD errors in fileserver and dasalvager

Fix missing newlines before =back commands.

Change-Id: If8e65c94f48c271c37c1b4bbec1b17d383c8375d
Reviewed-on: http://gerrit.openafs.org/2831
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>
(cherry picked from commit 10281b5be240707ed2eb75bdb68d9d23ff0011c8)
Reviewed-on: http://gerrit.openafs.org/2846
Reviewed-by: Russ Allbery <rra@stanford.edu>
Tested-by: Russ Allbery <rra@stanford.edu>