expo: Drop the render from expo_poll()

Within tests it is useful to be able to control rendering of the expo.
Drop the automatic call to expo_render() within expo_poll() and adjust
its callers to handle this instead.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/cedit.c b/boot/cedit.c
index 8faf230..56dc7c6 100644
--- a/boot/cedit.c
+++ b/boot/cedit.c
@@ -219,6 +219,10 @@
 	do {
 		struct expo_action act;
 
+		ret = expo_render(exp);
+		if (ret)
+			return log_msg_ret("cer", ret);
+
 		ret = expo_poll(exp, &act);
 		if (!ret)
 			cedit_do_action(exp, scn, vid_priv, &act);
diff --git a/boot/expo.c b/boot/expo.c
index ee8ffaf..94413ac 100644
--- a/boot/expo.c
+++ b/boot/expo.c
@@ -320,10 +320,6 @@
 {
 	int ichar, key, ret;
 
-	ret = expo_render(exp);
-	if (ret)
-		return log_msg_ret("ere", ret);
-
 	ichar = cli_ch_process(&exp->cch, 0);
 	if (!ichar) {
 		int i;