xen/pt: Fix flawed conversion to realize()

The conversion of xen_pt_initfn() to xen_pt_realize() blindly replaced
XEN_PT_ERR() by error_setg().  Several error conditions that did not
fail xen_pt_initfn() now fail xen_pt_realize().  Unsurprisingly, the
cleanup on these errors looks highly suspicious.

Revert the inappropriate replacements.

Fixes: 5a11d0f7549e24a10e178a9dc8ff5e698031d9a6
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Anthony Perard <anthony.perard@citrix.com>
Cc: Paul Durrant <paul@xen.org>
Cc: xen-devel@lists.xenproject.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paul Durrant <paul@xen.org>
Message-Id: <20200422130719.28225-10-armbru@redhat.com>

hw/xen/xen_pt.c

@@ -858,8 +858,8 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
 
     rc = xc_physdev_map_pirq(xen_xc, xen_domid, machine_irq, &pirq);
     if (rc < 0) {
-        error_setg_errno(errp, errno, "Mapping machine irq %u to"
-                         " pirq %i failed", machine_irq, pirq);
+        XEN_PT_ERR(d, "Mapping machine irq %u to pirq %i failed, (err: %d)\n",
+                   machine_irq, pirq, errno);
 
         /* Disable PCI intx assertion (turn on bit10 of devctl) */
         cmd |= PCI_COMMAND_INTX_DISABLE;
@@ -880,8 +880,8 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
                                        PCI_SLOT(d->devfn),
                                        e_intx);
         if (rc < 0) {
-            error_setg_errno(errp, errno, "Binding of interrupt %u failed",
-                             e_intx);
+            XEN_PT_ERR(d, "Binding of interrupt %i failed! (err: %d)\n",
+                       e_intx, errno);
 
             /* Disable PCI intx assertion (turn on bit10 of devctl) */
             cmd |= PCI_COMMAND_INTX_DISABLE;
@@ -889,8 +889,8 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
 
             if (xen_pt_mapped_machine_irq[machine_irq] == 0) {
                 if (xc_physdev_unmap_pirq(xen_xc, xen_domid, machine_irq)) {
-                    error_setg_errno(errp, errno, "Unmapping of machine"
-                            " interrupt %u failed", machine_irq);
+                    XEN_PT_ERR(d, "Unmapping of machine interrupt %i failed!"
+                               " (err: %d)\n", machine_irq, errno);
                 }
             }
             s->machine_irq = 0;