x86/irq: avoid use-after-free on error path in pirq_guest_bind()

This is XSA-83.

Coverity-ID: 1146952
Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -1590,8 +1590,7 @@ int pirq_guest_bind(struct vcpu *v, stru
             printk(XENLOG_G_INFO
                    "Cannot bind IRQ%d to dom%d. Out of memory.\n",
                    pirq->pirq, v->domain->domain_id);
-            rc = -ENOMEM;
-            goto out;
+            return -ENOMEM;
         }
 
         action = newaction;