hw/acpi/erst: Do not ignore Error* in realize handler

erst_realizefn() passes @errp to functions without checking for
failure.  If it runs into another failure, it trips error_setv()'s
assertion.

Use the ERRP_GUARD() macro and check *errp, as suggested in commit
ae7c80a ("error: New macro ERRP_GUARD()").

Cc: qemu-stable@nongnu.org
Fixes: f7e26ff ("ACPI ERST: support for ACPI ERST feature")
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-Id: <20231120130017.81286-1-philmd@linaro.org>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit 20bc501)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/acpi/erst.c

@@ -947,6 +947,7 @@ static const VMStateDescription erst_vmstate  = {
 
 static void erst_realizefn(PCIDevice *pci_dev, Error **errp)
 {
+    ERRP_GUARD();
     ERSTDeviceState *s = ACPIERST(pci_dev);
 
     trace_acpi_erst_realizefn_in();
@@ -964,9 +965,15 @@ static void erst_realizefn(PCIDevice *pci_dev, Error **errp)
 
     /* HostMemoryBackend size will be multiple of PAGE_SIZE */
     s->storage_size = object_property_get_int(OBJECT(s->hostmem), "size", errp);
+    if (*errp) {
+        return;
+    }
 
     /* Initialize backend storage and record_count */
     check_erst_backend_storage(s, errp);
+    if (*errp) {
+        return;
+    }
 
     /* BAR 0: Programming registers */
     memory_region_init_io(&s->iomem_mr, OBJECT(pci_dev), &erst_reg_ops, s,
@@ -977,6 +984,9 @@ static void erst_realizefn(PCIDevice *pci_dev, Error **errp)
     memory_region_init_ram(&s->exchange_mr, OBJECT(pci_dev),
                             "erst.exchange",
                             le32_to_cpu(s->header->record_size), errp);
+    if (*errp) {
+        return;
+    }
     pci_register_bar(pci_dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,
                         &s->exchange_mr);