bpftool: Properly close va_list 'ap' by va_end() on error

stable inclusion
from stable-5.10.53
commit 782d71e29b2960b0027aca046cd0077998cb54d9
bugzilla: 175574 https://gitee.com/openeuler/kernel/issues/I4DTUX

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=782d71e29b2960b0027aca046cd0077998cb54d9



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

commit bc832065 upstream.

va_list 'ap' was opened but not closed by va_end() in error case. It should
be closed by va_end() before the return.

Fixes: aa52bcbe ("tools: bpftool: Fix json dump crash on powerpc")
Signed-off-by: Gu Shengxian <gushengxian@yulong.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: https://lore.kernel.org/bpf/20210706013543.671114-1-gushengxian507419@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>