[media] lirc: might sleep error in lirc_dev_fop_read

[  101.457944] ------------[ cut here ]------------
[  101.457954] WARNING: CPU: 3 PID: 1819 at kernel/sched/core.c:7708 __might_sleep+0x7e/0x80
[  101.457960] do not call blocking ops when !TASK_RUNNING; state=1 set at [<ffffffffc0364bc2>] lirc_dev_fop_read+0x292/0x4e0 [lirc_dev]

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>