[swss]: Update sonic-swss submodule (#1091)

Including:
- [swss] a couple non-functional code cleanup changes
- [bufferorch] move buffer pool definitions together
- [orchagent] optimize the code structure
- [orchagent]: Fix hang problem caused by erase operation on empty map
- [orchagent]: Support port/LAG in multiple VLANs

Signed-off-by: Shu0T1an ChenG <shuche@microsoft.com>