staging: r8188eu: remove empty function _InitOperationMode

The definition of function _InitOperationMode is empty. Remove it.

Signed-off-by: Abdun Nihaal <abdun.nihaal@gmail.com>
Link: https://lore.kernel.org/r/07083cbb8b09957d2fcf9e5b70e0fd832ce53f35.1644422181.git.abdun.nihaal@gmail.com


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