[patch 2/2] Staging: intel_sst: cleanup naming a little

[Koul, Vinod]

> &sst_drv_ctx->streams[str_id].lock and &stream->lock are the same.
> The mutex_lock() uses &stream->lock so this makes things consistent and
> it's nicer to read as well.
> 
> Signed-off-by: Dan Carpenter <error27 at gmail.com>

Acked-by: Vinod Koul <vinod.koul at intel.com>