staging: r8188eu: remove unnecessary casts

Remove unnecessary casts in update_recvframe_attrib_88e.

The final bitwise-and limits the results to u8 or u16, respectively.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220305144117.1380534-5-martin@kaiser.cx


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