src/xvba_video_glx.c: Lock obj_output when used from put_surface_glx()

The function do_put_surface_glx() is used from the render_thread and
from put_surface_glx(). Make sure it is locked since it is accessed
from two threads.

src/xvba_video_glx.c

@@ -2406,6 +2406,7 @@ put_surface_glx(
     if (!gl_set_current_context(obj_output->gl_context, &old_cs))
         return VA_STATUS_ERROR_OPERATION_FAILED;
 
+    glx_output_surface_lock(obj_output);
     VAStatus status;
     status = do_put_surface_glx(
         driver_data,
@@ -2416,6 +2417,7 @@ put_surface_glx(
         cliprects, num_cliprects,
         flags
     );
+    glx_output_surface_unlock(obj_output);
 
     gl_set_current_context(&old_cs, NULL);
     return status;