[ Upstream commit 9c38f1f0 ]

Backspace is not working on some terminal emulators which do not send the
key code defined by terminfo. Terminals either send '^H' (8) or '^?' (127).
But currently only '^?' is handled. Let's also handle '^H' for those
terminals.
Signed-off-by: NChangbin Du <changbin.du@gmail.com>
Signed-off-by: NMasahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: NSasha Levin (Microsoft) <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>