x86_64: i8259.c trivial iso99 structure initialization

Index: test/arch/x86_64/kernel/i8259.c
===================================================================
@@ -158,14 +158,13 @@
 }
 
 static struct hw_interrupt_type i8259A_irq_type = {
-	"XT-PIC",
-	startup_8259A_irq,
-	shutdown_8259A_irq,
-	enable_8259A_irq,
-	disable_8259A_irq,
-	mask_and_ack_8259A,
-	end_8259A_irq,
-	NULL
+	.typename = "XT-PIC",
+	.startup = startup_8259A_irq,
+	.shutdown = shutdown_8259A_irq,
+	.enable = enable_8259A_irq,
+	.disable = disable_8259A_irq,
+	.ack = mask_and_ack_8259A,
+	.end = end_8259A_irq,
 };
 
 /*