gcc-6.0 warnings for scsi

[Arnd Bergmann]

gcc-6 found a couple of bugs in scsi drivers that are not
yet fixed in linux-next.

In all three cases, the code is indented in a rather misleading
way, but actually correct. I think it would be good to have
this fixed in 4.6, but no backports are needed even though
the problems have all been around for a while.