uutils coreutils cut Inconsistent Output Suppression with Newline Delimiters

The cut utility in uutils coreutils incorrectly handles the -s (only-delimited) option when a newline character is specified as the delimiter. The implementation fails to verify the only_delimited flag in the cut_fields_newline_char_delim function, causing the utility to print non-delimited lines that should have been suppressed. This can lead to unexpected data being passed to downstream scripts that rely on strict output filtering.