Staging: heci: fix wrong order of device_lock and file_lock

When the two locks are nested, the code should always first acquire file_lock,
and then acquire device_lock in order not to generate dead-lock race.

Signed-off-by: Dongxiao Xu <dongxiao.xu@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>