staging: xillybus: Blank lines add/remove

* Blank lines between a function call and its return status check were
  removed.
* Double blank lines were removed.
* Blank lines were added and removed as to silence checkpatch.pl --strict

Suggested-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>