Remove the __init and __exit modifiers from the VIO driver probe and
remove functions.

The driver functions should not be marked __init/__exit because they
can/will be called during runtime, not only at module init and exit.
Signed-off-by: NDan Streetman <ddstreet@ieee.org>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>