mfd: sm501: Fix reference leak on failed device registration

In the Linux kernel, the following vulnerability has been resolved: mfd: sm501: Fix reference leak on failed device registration When platform_device_register() fails in sm501_register_device(), the embedded struct device in pdev has already been initialized by device_initialize(), but the failure path only reports the error and returns without dropping the device reference for the current platform device: sm501_register_device() -> platform_device_register(pdev) -> device_initialize(&pdev->dev) -> setup_pdev_dma_masks(pdev) -> platform_device_add(pdev) This leads to a reference leak when platform_device_register() fails. Fix this by calling platform_device_put() before returning the error. The issue was identified by a static analysis tool I developed and confirmed by manual review.