i965: Flush batchbuffer containing the query on glQueryCounter.

This change fixes a regression with timer queries introduced with
commit 3eb6258. There the pending batchbuffer is flushed
only if glEndQuery is executed. This present change adds such
a flush to glQueryCounter which also schedules a value query
just like glEndQuery does. The patch fixes GPU timer queries
going mad from within osgviewer.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>
Signed-off-by: Mathias Froehlich <Mathias.Froehlich@web.de>
Cc: mesa-stable@lists.freedesktop.org

src/mesa/drivers/dri/i965/brw_queryobj.c

@@ -472,6 +472,8 @@ brw_query_counter(struct gl_context *ctx, struct gl_query_object *q)
    drm_intel_bo_unreference(query->bo);
    query->bo = drm_intel_bo_alloc(brw->bufmgr, "timestamp query", 4096, 4096);
    brw_write_timestamp(brw, query->bo, 0);
+
+   query->flushed = false;
 }
 
 /**