ivi-layout: apply opacity to weston_view correctly

update_opacity is only called when a ivi-surface is visible. But the
previous code also checks event masks redundantly. However if the event
happens when ivi-surface is invisible, opacity is not calculated. This
patch removes this redundant check to fix potential bug.

Signed-off-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
diff --git a/ivi-shell/ivi-layout.c b/ivi-shell/ivi-layout.c
index 4ad7a5f..f7c4f27 100644
--- a/ivi-shell/ivi-layout.c
+++ b/ivi-shell/ivi-layout.c
@@ -322,12 +322,9 @@
 	double layer_alpha = wl_fixed_to_double(ivilayer->prop.opacity);
 	double surf_alpha  = wl_fixed_to_double(ivisurf->prop.opacity);
 
-	if ((ivilayer->event_mask & IVI_NOTIFICATION_OPACITY) ||
-	    (ivisurf->event_mask  & IVI_NOTIFICATION_OPACITY)) {
-		tmpview = get_weston_view(ivisurf);
-		assert(tmpview != NULL);
-		tmpview->alpha = layer_alpha * surf_alpha;
-	}
+	tmpview = get_weston_view(ivisurf);
+	assert(tmpview != NULL);
+	tmpview->alpha = layer_alpha * surf_alpha;
 }
 
 static void