[sysprof] writer: clear values before setting counters

[Christian Hergert <chergert src gnome org>]

commit b4d5fdd5e4aae3122913591c967afbf966bf14b1
Author: Christian Hergert <chergert redhat com>
Date:   Thu May 17 11:38:34 2018 +0100

    writer: clear values before setting counters
    
    We have an annoying issue where we look at all fiends of a counter values
    chunk in the counter set frame. So we need those values set to zero. If
    we are passed fewer counter values than can fit in the frame, we leave
    some of that data uninitialized. This ensures that it is cleared.

 lib/capture/sp-capture-writer.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/lib/capture/sp-capture-writer.c b/lib/capture/sp-capture-writer.c
index a1fa220..8ccc534 100644
--- a/lib/capture/sp-capture-writer.c
+++ b/lib/capture/sp-capture-writer.c
@@ -1120,6 +1120,8 @@ sp_capture_writer_set_counters (SpCaptureWriter             *self,
   if (!set)
     return FALSE;
 
+  memset (set, 0, len);
+
   sp_capture_writer_frame_init (&set->frame,
                                 len,
                                 cpu,