LU-17444 utils: fix fd leak after conversion to llapi_root_path_open

LU-17444 utils: fix fd leak after conversion to llapi_root_path_open

Conversions to llapi_root_path_open missed a few close() calls, leading
to fd leaks.

These should be obvious enough to regroup in a single commit.

Fixes: 7154244354e3 ("LU-16786 utils: Replace open call to WANT_FD")
Change-Id: I3af25ef2981367bfaea7f5280972f84bee09a5c2
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53736
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Stephane Thiell <sthiell@stanford.edu>
Reviewed-by: Etienne AUJAMES <eaujames@ddn.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>