x86/irq: Improve definition of VECTOR_SHUTDOWN et al

These values are used with IS_ERR(), so it's more intuitive to define
them like a standard PTR_ERR() of a negative errno.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/146835e8-c086-4e85-7ece-bcba6795e6db@gmail.com

arch/x86/include/asm/hw_irq.h

@@ -153,8 +153,8 @@ extern char irq_entries_start[];
 extern char spurious_entries_start[];
 
 #define VECTOR_UNUSED		NULL
-#define VECTOR_SHUTDOWN		((void *)~0UL)
-#define VECTOR_RETRIGGERED	((void *)~1UL)
+#define VECTOR_SHUTDOWN		((void *)-1L)
+#define VECTOR_RETRIGGERED	((void *)-2L)
 
 typedef struct irq_desc* vector_irq_t[NR_VECTORS];
 DECLARE_PER_CPU(vector_irq_t, vector_irq);