[media] lirc_zilog: fix spinning rx thread

We were calling schedule_timeout with the rx thread's task state still
at TASK_RUNNING, which it shouldn't be. Make sure we call
set_current_state(TASK_INTERRUPTIBLE) *before* schedule_timeout, and
we're all good here. I believe this problem was mistakenly introduced in
commit 5bd6b0464b68d429bc8a3fe6595d19c39dfc4d95, and I'm not sure how I
missed it before, as I swear I tested the patchset that was included in,
but alas, stuff happens...

Acked-by: Andy Walls <awalls@md.metrocast.net>
CC: stable@kernel.org
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>