plugins/loader: populate target_name with target_name()

We have a function we can call for this, lets not rely on macros that
stop us building once.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20250304222439.2035603-22-alex.bennee@linaro.org>

plugins/loader.c

@@ -297,7 +297,7 @@ int qemu_plugin_load_list(QemuPluginList *head, Error **errp)
     struct qemu_plugin_desc *desc, *next;
     g_autofree qemu_info_t *info = g_new0(qemu_info_t, 1);
 
-    info->target_name = TARGET_NAME;
+    info->target_name = target_name();
     info->version.min = QEMU_PLUGIN_MIN_VERSION;
     info->version.cur = QEMU_PLUGIN_VERSION;
 #ifndef CONFIG_USER_ONLY