x86/irq: Drop unlikely before IS_ERR_OR_NULL

IS_ERR_OR_NULL already contain an unlikely compiler flag. Drop it.
Signed-off-by: NGeliang Tang <geliangtang@163.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/03d18502ed7ed417f136c091f417d2d88c147ec6.1443667610.git.geliangtang@163.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/irq_64.c

@@ -72,7 +72,7 @@ bool handle_irq(struct irq_desc *desc, struct pt_regs *regs)
 {
 	stack_overflow_check(regs);
 
-	if (unlikely(IS_ERR_OR_NULL(desc)))
+	if (IS_ERR_OR_NULL(desc))
 		return false;
 
 	generic_handle_irq_desc(desc);