sensor: fix typo in variable name

"Get Device SDR" usses a wrong variable name.

Signed-off-by: Heiko Thiery <heiko.thiery@kontron.com>
interface: aardvark: refactored the rx filter

Signed-off-by: Heiko Thiery <heiko.thiery@kontron.com>
interface: aardvark: add slave_address to __init__

Signed-off-by: Heiko Thiery <heiko.thiery@kontron.com>
Merge branch 'master' of https://github.com/kontron/python-ipmi