Unquoted argument in {{logger}} call leads to invalid argument warnings

At times the wsrep_sst_mariabackup script will generate log messages like:

This is due to the 2nd logger call here:

            wsrep_log_info "Contents of datadir:"

            wsrep_log_info $(ls -l "$dir/"*)

which is missing quotes around the subshell argument.
As the "ls l" produces tends to produce output starting with -rw-rw-rw the missing quotes lead to "-r" being misinterpreted as a command line option to the logger tool