[Backport] [202205] Fix issue: should always check return value of a function if the function may return None#356

yxieca merged 2 commits intosonic-net:202205sonic-net/sonic-platform-common:202205from

Junchao-Mellanox:backport-pr-350-202205Junchao-Mellanox/sonic-platform-common:backport-pr-350-202205Copy head branch name to clipboard