COSA/SRP driver: The semaphore channel_data.rsem is used as a mutex,
convert it to the mutex API
Signed-off-by: NMatthias Kaehlcke <matthias@kaehlcke.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>