Shorten variable names. This also compacts the code a bit.

	device_mce		=> mce_dev
	mce_device_initialized	=> mce_dev_initialized
	mce_attribute		=> mce_attrs

[ Impact: cleanup ]
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NHidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>