x86/platform/uv: Use apic_ack_irq()

To address the EBUSY fail of interrupt affinity settings in case that the
previous setting has not been cleaned up yet, use the new apic_ack_irq()
function instead of the special uv_ack_apic() implementation which is
merily a wrapper around ack_APIC_irq().

Preparatory change for the real fix

Fixes: dccfe3147b ("x86/vector: Simplify vector move cleanup")
Reported-by: Song Liu <liu.song.a23@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Song Liu <songliubraving@fb.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: stable@vger.kernel.org
Cc: Mike Travis <mike.travis@hpe.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tariq Toukan <tariqt@mellanox.com>
Link: https://lkml.kernel.org/r/20180604162224.721691398@linutronix.de

arch/x86/platform/uv/uv_irq.c

@@ -47,11 +47,6 @@ static void uv_program_mmr(struct irq_cfg *cfg, struct uv_irq_2_mmr_pnode *info)
 
 static void uv_noop(struct irq_data *data) { }
 
-static void uv_ack_apic(struct irq_data *data)
-{
-	ack_APIC_irq();
-}
-
 static int
 uv_set_irq_affinity(struct irq_data *data, const struct cpumask *mask,
 		    bool force)
@@ -73,7 +68,7 @@ static struct irq_chip uv_irq_chip = {
 	.name			= "UV-CORE",
 	.irq_mask		= uv_noop,
 	.irq_unmask		= uv_noop,
-	.irq_eoi		= uv_ack_apic,
+	.irq_eoi		= apic_ack_irq,
 	.irq_set_affinity	= uv_set_irq_affinity,
 };