Remove unused mclass variable in mmix_function_outgoing_value

From-SVN: r46748

gcc/config/mmix/mmix.c

@@ -530,7 +530,6 @@ mmix_function_outgoing_value (valtype, func)
      tree func ATTRIBUTE_UNUSED;
 {
   enum machine_mode mode = TYPE_MODE (valtype);
-  enum mode_class mclass = GET_MODE_CLASS (mode);
   enum machine_mode cmode;
   int first_val_regnum = MMIX_OUTGOING_RETURN_VALUE_REGNUM;
   rtx vec[MMIX_MAX_REGS_FOR_VALUE];