LU-14208 utils: remove copy_file_range() usage from copytool

LU-14208 utils: remove copy_file_range() usage from copytool

Revert the lhsmtool_posix part of "LU-11621 utils: optimize
lhsmtool_posix with copy_file_range()". This is failing sanity-hsm
test_55() on RHEL 8.3.

Test-Parameters: clientdistro=el8.3 serverdistro=el8.3 testlist=sanity-hsm
Signed-off-by: John L. Hammond <jhammond@whamcloud.com>
Change-Id: I0b410c2bb5f56a32c10f0ec39190735908cbb556
Reviewed-on: https://review.whamcloud.com/40966
Reviewed-by: James Simmons <jsimmons@infradead.org>
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>