On platforms not using the GNU coreutils, namely MacOs, readlink doesn't
have a canonicalize option.
Use it only when availabe, otherwise use the relative paths.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Change-Id: I798e6320dda78c5d9b33a2568b663c57d35d42b3
Reviewed-on: https://review.lttng.org/c/babeltrace/+/1749
Reviewed-by: Philippe Proulx <eeppeliteloop@gmail.com>