intel_th: Fix a double put_device() in error path

intel_th: Fix a double put_device() in error path

Commit a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices")
factored out intel_th_subdevice_alloc() from intel_th_populate(), but got
the error path wrong, resulting in two instances of a double put_device()
on a freshly initialized, but not 'added' device.

Fix this by only doing one put_device() in the error path.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: a753bfcfdb1f ("intel_th: Make the switch allocate its subdevices")
Reported-by: Wen Yang <wenyang@linux.alibaba.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: stable@vger.kernel.org # v4.14+
Link: https://lore.kernel.org/r/20191120130806.44028-2-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>