i2o: cleanup some exit paths

This is just a cleanup and doesn't change how the code works.

The original code had a mix of returns and gotos so I changed everything
to just return directly.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>