common, menu: do not trigger timeout again, if a line is read

Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Jason Hobbs <jason.hobbs@calxeda.com>
Acked-by: Jason Hobbs <jason.hobbs@calxeda.com>
diff --git a/common/menu.c b/common/menu.c
index 754a9f9..aa16c9a 100644
--- a/common/menu.c
+++ b/common/menu.c
@@ -236,8 +236,10 @@
 		if (readret >= 0) {
 			choice_item = menu_item_by_key(m, cbuf);
 
-			if (!choice_item)
+			if (!choice_item) {
 				printf("%s not found\n", cbuf);
+				m->timeout = 0;
+			}
 		} else {
 			puts("^C\n");
 			return -EINTR;