[submodule]: update sonic-swss (sonic-net#11094)

* b12af41 2022-06-09 | [fpmsyncd] don't manipulate route weight (sonic-net#2320) (HEAD, origin/master, origin/HEAD) [Ying Xie]
* a3f4fbb 2022-06-09 | Combine PGs in buffermgrd (sonic-net#2281) [bingwang-ms]

Signed-off-by: Guohan Lu <lguohan@gmail.com>