staging: skein: fix block comment style

Use a separate line for the opening marker of a comment block,
a leading asterisk in front of subsequent lines in the block comment,
and a separate line for the closing marker of the comment block.

This patch fixes the checkpatch.pl warnings:

WARNING: Block comments use a trailing */ on a separate line
WARNING: Block comments use * on subsequent lines

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>