[PATCH] x86/IRQ: constrain creator-domain-ID assertion

[Jan Beulich]

If init_one_irq_desc() fails, ->arch.creator_domid won't be set to the
expected value, and hence the assertion may trigger. Limit it to just
the success case of that function call.

Fixes: 92d9101eab ("x86: allow stubdom access to irq created for msi")
Reported-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
Signed-off-by: Jan Beulich <jbeul...@suse.com>

--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -289,9 +289,9 @@ int create_irq(nodeid_t node, bool grant
                 mask = NULL;
         }
         ret = assign_irq_vector(irq, mask);
-    }
 
-    ASSERT(desc->arch.creator_domid == DOMID_INVALID);
+        ASSERT(desc->arch.creator_domid == DOMID_INVALID);
+    }
 
     if (ret < 0)
     {