staging: r8188eu: convert rtw_p2p_get_peer_devaddr_by_invitation to return void

rtw_p2p_get_peer_devaddr_by_invitation always returns 0 and it's return
value is not used. Convert it to return void.

Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Abdun Nihaal <abdun.nihaal@gmail.com>
Link: https://lore.kernel.org/r/06e2dce5de14c1abe457a40ec9ca597a06095437.1643466748.git.abdun.nihaal@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>