staging: skein: Convert local rotl_64 to kernel's rol64

Remove the local inline and use the generic kernel rol64 instead.

Miscellanea:

o Added a newline between a multiple line macro for consistency
  with the other multiple line macros

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>