staging: r8188eu: remove redundant parameter

The rtl8188eu_xmitframe_complete function takes two parameters: adapter
and xmit_priv. xmit_priv is part of struct adapter, this parameter can be
removed.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Link: https://lore.kernel.org/r/20230123205342.229589-13-martin@kaiser.cx


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