afsmonitor: avoid showing full perf stats garbage

afsmonitor: avoid showing full perf stats garbage

Unfortunately, the full perf stats contain timeval structures which
do not have the same size everywhere. Avoid displaying gargbage,
but at least try to show the overall stats.

Change-Id: I9245b333ac15212194490e1a3f11b7c98dfaadda
Reviewed-on: http://gerrit.openafs.org/1730
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>