staging: r8188eu: Remove pointless "alignment" entry in recv_frame

This alignment entry in union recv_frame does nothing. It certainly
dues not ensure alignment.

Suggested-by:  <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Jes.Sorensen@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>