RISC-V: stringL_indexof_char instruction has wrong format string

The format of stringL_indexof_char is just a copy and paste from stringU_indexof_char. It should be `StringLatin1` instead of `StringUTF16`.


instruct stringL_indexof_char(iRegP_R11 str1, iRegI_R12 cnt1, iRegI_R13 ch,
                              iRegI_R10 result, iRegINoSp tmp1, iRegINoSp tmp2,
                              iRegINoSp tmp3, iRegINoSp tmp4, rFlagsReg cr)
%{
  match(Set result (StrIndexOfChar (Binary str1 cnt1) ch));
  predicate(!UseRVV && (((StrIndexOfCharNode*)n)->encoding() == StrIntrinsicNode::L));
  effect(USE_KILL str1, USE_KILL cnt1, USE_KILL ch, TEMP_DEF result,
         TEMP tmp1, TEMP tmp2, TEMP tmp3, TEMP tmp4, KILL cr);

  format %{ "StringUTF16 IndexOf char[] $str1,$cnt1,$ch -> $result" %} ====> Should be StringLatin1 here.
  ins_encode %{
    __ string_indexof_char($str1$$Register, $cnt1$$Register, $ch$$Register,
                           $result$$Register, $tmp1$$Register, $tmp2$$Register,
                           $tmp3$$Register, $tmp4$$Register, true /* isL */);
  %}
  ins_pipe(pipe_class_memory);
%}