[libpeas] Fix PeasEngine virtual annotations

[Garrett Regier <gregier src gnome org>]

commit 743ca63655ac23c24efed5aad33479fa1f4faadf
Author: Garrett Regier <garrettregier gmail com>
Date:   Fri Mar 24 11:14:14 2017 -0700

    Fix PeasEngine virtual annotations
    
    These comments are invalid as the virtual
    functions do not have a return value.

 libpeas/peas-engine.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/libpeas/peas-engine.c b/libpeas/peas-engine.c
index f56cd37..3b35145 100644
--- a/libpeas/peas-engine.c
+++ b/libpeas/peas-engine.c
@@ -1166,7 +1166,7 @@ error:
 }
 
 /**
- * peas_engine_load_plugin: (virtual load_plugin)
+ * peas_engine_load_plugin:
  * @engine: A #PeasEngine.
  * @info: A #PeasPluginInfo.
  *
@@ -1240,7 +1240,7 @@ peas_engine_unload_plugin_real (PeasEngine     *engine,
 }
 
 /**
- * peas_engine_unload_plugin: (virtual unload_plugin)
+ * peas_engine_unload_plugin:
  * @engine: A #PeasEngine.
  * @info: A #PeasPluginInfo.
  *