LU-17000 utils: Use correct printf specifier for lustre_rsync.c

LU-17000 utils: Use correct printf specifier for lustre_c

In lr_copy_xattr() use "%s" for "char *" and "%zd"
for "ssize_t" data type.

Change 'struct lr_info' fields xsize and xvsize from size_t
to ssize_t as extended attribute functions can return
negative values

Test-Parameters: trivial testlist=lustre-rsync-test
CoverityID: 397866 ("Invalid type in argument to printf format specifier")
CoverityID: 397573 ("Invalid type in argument to printf format specifier")
Signed-off-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Change-Id: Idd7c4f81c1a1751c595c86b10493aab6f959059f
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/55154
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>