staging: skein: threefish_block.c Remove blank lines

Make suggested checkpatch modification for

CHECK: Please don't use multiple blank lines

Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Walt Feasel <waltfeasel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>