intr_disabled() tests removed

- we don't need to test this in kernel as we always have interrupts
  disabled

- if interrupts are enabled in kernel, it is only at very carefully
  chosen places. There are no such places now.

kernel/system/do_irqctl.c

@@ -137,8 +137,6 @@ irq_hook_t *hook;
  */
   int proc_nr;
 
-  vmassert(intr_disabled());
-
   /* As a side-effect, the interrupt handler gathers random information by 
    * timestamping the interrupt events. This is used for /dev/random.
    */
@@ -158,7 +156,6 @@ irq_hook_t *hook;
   priv(proc_addr(proc_nr))->s_int_pending |= (1 << hook->notify_id);
 
   /* Build notification message and return. */
-  vmassert(intr_disabled());
   mini_notify(proc_addr(HARDWARE), hook->proc_nr_e);
   return(hook->policy & IRQ_REENABLE);
 }