staging: r8188eu: simplify error handling

Simplify the error handling in validate_recv_data_frame. The function does
not have to do any cleanup for errors, we can return immediately.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220403165438.357728-5-martin@kaiser.cx


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