[drivers][serial/v2] fix missing break after -RT_EPERM when buf size is 0 - #11397

[drivers][serial/v2] fix missing break after -RT_EPERM when buf size is 0#11397

Rbb666 merged 2 commits into

RT-Thread:masterRT-Thread/rt-thread:masterfrom

kaidegit:fix/serial-v2-missing-breakkaidegit/rt-thread:fix/serial-v2-missing-breakCopy head branch name to clipboard