irq_free_hwirqs() always calls irq_free_descs() with a cnt == 0
which makes it a no-op since the interrupt count to free is
decremented in itself.
Fixes: 7b6ef1262549f6afc5c881aaef80beb8fd15f908
Signed-off-by: Keith Busch <keith.busch@intel.com>
Acked-by: David Rientjes <rientjes@google.com>
Link: http://lkml.kernel.org/r/1404167084-8070-1-git-send-email-keith.busch@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
  */
 void irq_free_hwirqs(unsigned int from, int cnt)
 {
-       int i;
+       int i, j;
 
-       for (i = from; cnt > 0; i++, cnt--) {
+       for (i = from, j = cnt; j > 0; i++, j--) {
                irq_set_status_flags(i, _IRQ_NOREQUEST | _IRQ_NOPROBE);
                arch_teardown_hwirq(i);
        }