block/qapi: make @node-name in @BlockDeviceInfo non-optional

Since commit 15489c769b ("block: auto-generated node-names"), if the
node name of a block driver state is not explicitly specified, it
will be auto-generated.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Message-ID: <20250702123204.325470-3-f.ebner@proxmox.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

block/qapi.c

@@ -75,9 +75,7 @@ BlockDeviceInfo *bdrv_block_device_info(BlockBackend *blk,
         .no_flush       = !!(bs->open_flags & BDRV_O_NO_FLUSH),
     };
 
-    if (bs->node_name[0]) {
-        info->node_name = g_strdup(bs->node_name);
-    }
+    info->node_name = g_strdup(bs->node_name);
 
     children_list_tail = &info->children;
     QLIST_FOREACH(child, &bs->children, next) {

qapi/block-core.json

@@ -573,7 +573,7 @@
 # Since: 0.14
 ##
 { 'struct': 'BlockDeviceInfo',
-  'data': { 'file': 'str', '*node-name': 'str', 'ro': 'bool', 'drv': 'str',
+  'data': { 'file': 'str', 'node-name': 'str', 'ro': 'bool', 'drv': 'str',
             '*backing_file': 'str', 'backing_file_depth': 'int',
             'children': ['BlockdevChild'],
             'active': 'bool', 'encrypted': 'bool',