amt: remove unnecessary (void*) conversions

Remove unnecessary void* type castings.

Signed-off-by: Yu Zhe <yuzhe@nfschina.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Link: https://lore.kernel.org/r/20220621021648.2544-1-yuzhe@nfschina.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>