drm/sti: debug fps reset

Reset the fps debug information when 'fps_show' is updated.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
diff --git a/drivers/gpu/drm/sti/sti_drv.c b/drivers/gpu/drm/sti/sti_drv.c
index 7cdccb0..e6c1646 100644
--- a/drivers/gpu/drm/sti/sti_drv.c
+++ b/drivers/gpu/drm/sti/sti_drv.c
@@ -58,7 +58,9 @@ static int sti_drm_fps_set(void *data, u64 val)
 	list_for_each_entry(p, &drm_dev->mode_config.plane_list, head) {
 		struct sti_plane *plane = to_sti_plane(p);
 
+		memset(&plane->fps_info, 0, sizeof(plane->fps_info));
 		plane->fps_info.output = (val >> i) & 1;
+
 		i++;
 	}