xstat: remove unused call info function

Remove the dead function PrintCallInfo(), which was replaced
by print_cmCallStats() long, long ago.

Change-Id: Id67323d66cc498f77e55f173218547ad5d4223c7
Reviewed-on: http://gerrit.openafs.org/8740
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>