Staging: vt6655: Checkpatch fix: empty c99 comments

This patch fixes some of the following checkpatch.pl errors in mac.h:
ERROR: do not use C99 // comments

This patch truncates statements which are followed by empty c99
comments.
Signed-off-by: Emrys Bayliss <emrys@paradise.net.nz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>