MIPS: irq: Avoid an unused-variable error

When CONFIG_IRQ_DOMAIN is set, there is a warning:
arch/mips/kernel/irq.c:114:19: error: unused variable 'desc' [-Werror=unused-variable]
  114 |  struct irq_desc *desc;
      |                   ^~~~

This variable is unused, let's remove it.

Signed-off-by: Yanteng Si <[email protected]>
Signed-off-by: Marc Zyngier <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: sterling-teng

arch/mips/kernel/irq.c

@@ -111,8 +111,6 @@ void __irq_entry do_IRQ(unsigned int irq)
 #ifdef CONFIG_IRQ_DOMAIN
 void __irq_entry do_domain_IRQ(struct irq_domain *domain, unsigned int hwirq)
 {
-	struct irq_desc *desc;
-
 	irq_enter();
 	check_stack_overflow();
 	generic_handle_domain_irq(domain, hwirq);