[PATCH] app/testpmd: fix set cores list string size

[fengchengwen]

Acked-by: Chengwen Feng <fengchengwen at huawei.com>

On 2025/7/8 20:51, Dengdui Huang wrote:
> The cmdline_fixed_string_t has a length of only 128, which will
> become insufficient when there are many cores, so it should be
> replaced with a cmdline_multi_string_t of larger capacity.
> 
> Fixes: af75078fece3 ("first public release")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Dengdui Huang <huangdengdui at huawei.com>