FSSYNC-Client: Consistent use of partition name

FSSYNC-Client:  Consistent use of partition name

Over time the FSSYNC code has collected examples where the partition
path is passed rather than the partition name.  In Unix this is the
same (/vicepX), but on windows the path is the DOS device (C:).

This checkin changes FSSYNC client code to always use the partition
name.

This checkin does not address FSSYNC server or SALVSYNC.

Change-Id: I3c5b63103ab0cbd6c2c6c73b9dc737eca22b7d4c
Reviewed-on: http://gerrit.openafs.org/5521
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Jeffrey Altman <jaltman@openafs.org>