Remove return of value for afs_MarinerLogFetch()

Remove return of value for afs_MarinerLogFetch()

afs_MarinerLogFetch(), a void routine, attempts to return a value.
While gcc (amongst others) merely issues a warning about this, the
Sun Studio C compiler gets cranky (at least on x86) and treats it as
a hard error, thereby aborting the build. Since there actually is no
value to return, this update simply removes the attempt.

Change-Id: Ic89fb05380a25a433f9c3b9fa57962f215348d95
Reviewed-on: http://gerrit.openafs.org/1574
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>