[submodule]: update sonic-linux-kernel

3107549 2018-10-06 | uart: fix race between uart_put_char() and uart_shutdown() (sonic-net#67) (azure/master) [lguohan]
95db35e 2018-10-02 | [mellanox]: Update kernel with the latest upstream patches. (sonic-net#62) [sholeksandr]

Signed-off-by: Guohan Lu <gulv@microsoft.com>