smbios: clear smbios_type4_count before building tables

it will help to keep type 4 tables accounting correct in case
SMBIOS tables are built multiple times.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Tested-by: Fiona Ebner <f.ebner@proxmox.com>
Message-Id: <20240314152302.2324164-15-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c
index 0ab77b5..48713aa 100644
--- a/hw/smbios/smbios.c
+++ b/hw/smbios/smbios.c
@@ -1096,6 +1096,7 @@
            ep_type == SMBIOS_ENTRY_POINT_TYPE_64);
 
     g_free(smbios_tables);
+    smbios_type4_count = 0;
     smbios_tables = g_memdup2(usr_blobs, usr_blobs_len);
     smbios_tables_len = usr_blobs_len;
     smbios_table_max = usr_table_max;