devtmpfsd: fix task state handling

- Set the state to TASK_INTERRUPTIBLE using __set_current_state()
  instead of set_current_state() as the spin_unlock is an implicit memory
  barrier.

- After return from schedule(), there is no need to set the current
  state to TASK_RUNNING - a call to schedule() always returns in
  TASK_RUNNING state.

Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>