consolemap: Fix a memory leaking bug in drivers/tty/vt/consolemap.c

mainline inclusion
from mainline-5.3
commit 84ecc2f6
category: bugfix
bugzilla: 13690
CVE: CVE-2019-12379

-------------------------------------------------

In function con_insert_unipair(), when allocation for p2 and p1[n]
fails, ENOMEM is returned, but previously allocated p1 is not freed,
remains as leaking memory. Thus we should free p1 as well when this
allocation fails.

Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Yue Haibing <yuehaibing@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>