[gnome-builder] fix some static analysis warnings

[Christian Hergert <chergert src gnome org>]

commit a8bc71e7690283f5b415f096e01aaf39a52c57ca
Author: Patrick Griffis <tingping tingping se>
Date:   Fri May 8 10:58:29 2015 -0700

    fix some static analysis warnings
    
    Mostly minor fixes such as unused variables

 libide/clang/ide-clang-completion-provider.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/libide/clang/ide-clang-completion-provider.c b/libide/clang/ide-clang-completion-provider.c
index d9cd3a8..b417ddb 100644
--- a/libide/clang/ide-clang-completion-provider.c
+++ b/libide/clang/ide-clang-completion-provider.c
@@ -220,7 +220,8 @@ ide_clang_completion_provider_complete_cb (GObject      *object,
       goto failure;
     }
 
-  g_ptr_array_free (self->last_results, TRUE);
+  if (self->last_results != NULL)
+    g_ptr_array_free (self->last_results, TRUE);
   self->last_results = g_ptr_array_ref (ar);
 
   gtk_source_completion_context_get_iter (state->context, &iter);