[OpenMP][Tests][NFC] rename macro to avoid naming clash

Rename a macro use missed in e0f3acc5d34aa

GitOrigin-RevId: 2fbce374c8fb6f847bf6f4f023fe753989f49aa1
diff --git a/tools/multiplex/tests/custom_data_storage/first-tool.h b/tools/multiplex/tests/custom_data_storage/first-tool.h
index 7a0bbed..91cb34e 100644
--- a/tools/multiplex/tests/custom_data_storage/first-tool.h
+++ b/tools/multiplex/tests/custom_data_storage/first-tool.h
@@ -247,7 +247,7 @@
       printf("0: Could not register callback '" #name "'\n");                  \
   } while (0)
 
-#define register_ompt_callback2(name) register_callback2_t(name, name##_t)
+#define register_ompt_callback2(name) register_ompt_callback2_t(name, name##_t)
 
 int ompt_cds_initialize(ompt_function_lookup_t lookup, int initial_device_num,
                         ompt_data_t *tool_data) {