sh: fix INTC to use set_irq_chained_handler() for redirects

This patch updates the shared INTC code to use
set_irq_chained_handler() for intc_redirect_irq().

With this in place request_irq() on a merged irq
which has been redirected will now return -EINVAL
instead of 0 together with a crash. This thanks to
the protection of the IRQ_NOREQUEST flag set for
chained interrupt handlers.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

drivers/sh/intc.c

@@ -896,8 +896,8 @@ void __init register_intc_controller(struct intc_desc *desc)
 			vect2->enum_id = 0;
 
 			/* redirect this interrupts to the first one */
-			set_irq_chip_and_handler_name(irq2, &d->chip,
-					intc_redirect_irq, "redirect");
+			set_irq_chained_handler(irq2, intc_redirect_irq);
+			set_irq_chip(irq2, &d->chip);
 			set_irq_data(irq2, (void *)irq);
 		}
 	}