Currently, stm_register_device() makes the device visible and then
proceeds to initializing spinlocks and other properties, which leaves
a window when the device can already be opened but is not yet fully
operational.
Fix this by reversing the initialization order.
Reported-by: Alan Cox <alan.cox@intel.com> Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Reviewed-by: Laurent Fert <laurent.fert@intel.com>