scsi: libsas: Fix some indentation in libsas.h

Currently much indentation in this file is done with whitespaces instead of
tabs, which can make reading difficult, so fix this up.

Some other little minor tidy-up is done, but this file still has many other
checkpatch warnings (generally linelength > 80 or function arguments have
no identifier names).

All libsas code can be audited for checkpatch issues later.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>