patch 9.0.0653: BS and DEL do not work properly in an interacive shell

Problem:    BS and DEL do not work properly in an interacive shell. (Gary
            Johnson)
Solution:   Adjust the length for replaced codes.
diff --git a/src/os_unix.c b/src/os_unix.c
index e86e308..20e979c 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -5106,7 +5106,7 @@
 			    }
 			}
 
-			term_replace_bs_del_keycode(ta_buf, ta_len, len);
+			len = term_replace_bs_del_keycode(ta_buf, ta_len, len);
 
 			/*
 			 * For pipes: echo the typed characters.