use vtysh : The backspace key can only move forward and cannot delete characters

[hansengao]

Description

I got the same on:
arch: mips
gcc:
Using built-in specs.
COLLECT_GCC=/opt/toolchain/rtk-ms-2.0.0-linux-mips-3.18-4.8.5-u0.9.33-toolchain//bin/mips-linux-uclibc-xgcc
COLLECT_LTO_WRAPPER=/opt/toolchain/rtk-ms-2.0.0-linux-mips-3.18-4.8.5-u0.9.33-toolchain/bin/../libexec/gcc/mips-linux-uclibc/4.8.5/lto-wrapper
Target: mips-linux-uclibc
Configured with: Realtek SDK Builder release 4.8
Thread model: posix
gcc version 4.8.5 20150209 (prerelease) (Realtek MSDK-4.8.5p1 Build 2536)

libyang: libyang-1.0.184
readline 8.0
pcre 8.44
c-ares-1.12.0
frr: frr-7.5.1

Version

/tmp # ./vtysh

Hello, this is FRRouting (version 7.5.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5#

How to reproduce

/tmp # ./vtysh

Hello, this is FRRouting (version 7.5.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5#

Expected behavior

/tmp # ./vtysh

Hello, this is FRRouting (version 7.5.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5#

Actual behavior

/tmp # ./vtysh

Hello, this is FRRouting (version 7.5.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5#

Additional context

/tmp # ./vtysh

Hello, this is FRRouting (version 7.5.1).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5#
Realtek_0CA5D5# configure

Checklist

• I have searched the open issues for this bug.
• I have not included sensitive information in this report.