staging: r8188eu: use PTR_ALIGN() instead of RND4()

Use in-kernel PTR_ALIGN() instead of custom RND4().

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20220407125742.7814-2-straube.linux@gmail.com


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