LU-10508 utils: use callvpe() in lustre_rsync

LU-10508 utils: use callvpe() in lustre_rsync

Add callvpe() to lustre/utils as a replacement for system() in cases
where the command string includes arbitrary pathnames. In
lustre_rsync, replace calls to system() with calls to callvpe().

Test-Parameters: trivial testlist=lustre-rsync-test
Signed-off-by: John L. Hammond <john.hammond@intel.com>
Change-Id: Id5ae7e25e14346a1293497c2caa221513d0ee9f3
Reviewed-on: https://review.whamcloud.com/30869
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>