x86, mce: Call put_device on device_register failure

This patch adds a call to put_device() when the device_register() call
has failed. This is required so that the last reference to the device is
given up.

Signed-off-by: Levente Kurusa <levex@linux.com>
Link: http://lkml.kernel.org/r/5298F900.9000208@linux.com


Signed-off-by: Borislav Petkov <bp@suse.de>