doc: afs_compile_et formatting fixes

doc: afs_compile_et formatting fixes

Fix two pod formatting errors and remove one trailing
whitespace characters.

Reviewed-on: http://gerrit.openafs.org/10719
Reviewed-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Tested-by: Ken Dreyer <ktdreyer@ktdreyer.com>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit de8ff76f8767246431115bf04a1475a0cf3ad28a)

Change-Id: Ie2da8d8bf55a6ef9a067be06eb6626fc3dfd57fc
Reviewed-on: http://gerrit.openafs.org/11222
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>