x86/mce: Improve mcheck_init_device() error handling

Check return code of every function called by mcheck_init_device().

Signed-off-by: Mathieu Souchaud <mattieu.souchaud@free.fr>
Link: http://lkml.kernel.org/r/1399151031-19905-1-git-send-email-mattieu.souchaud@free.fr


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