qapi/block-core: Drop temporary 'prefix'

Recent commit "qapi: Smarter camel_to_upper() to reduce need for
'prefix'" added a temporary 'prefix' to delay changing the generated
code.

Revert it.  This improves XDbgBlockGraphNodeType's generated
enumeration constant prefix from
X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND to
XDBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240904111836.3273842-4-armbru@redhat.com>
diff --git a/block.c b/block.c
index c317de9..7d90007 100644
--- a/block.c
+++ b/block.c
@@ -6351,7 +6351,7 @@
         if (!*name) {
             name = allocated_name = blk_get_attached_dev_id(blk);
         }
-        xdbg_graph_add_node(gr, blk, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND,
+        xdbg_graph_add_node(gr, blk, XDBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_BACKEND,
                            name);
         g_free(allocated_name);
         if (blk_root(blk)) {
@@ -6364,7 +6364,7 @@
              job = block_job_next_locked(job)) {
             GSList *el;
 
-            xdbg_graph_add_node(gr, job, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
+            xdbg_graph_add_node(gr, job, XDBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_JOB,
                                 job->job.id);
             for (el = job->nodes; el; el = el->next) {
                 xdbg_graph_add_edge(gr, job, (BdrvChild *)el->data);
@@ -6373,7 +6373,7 @@
     }
 
     QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
-        xdbg_graph_add_node(gr, bs, X_DBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER,
+        xdbg_graph_add_node(gr, bs, XDBG_BLOCK_GRAPH_NODE_TYPE_BLOCK_DRIVER,
                            bs->node_name);
         QLIST_FOREACH(child, &bs->children, next) {
             xdbg_graph_add_edge(gr, bs, child);