As far as I know SPC-4 does not allow unaligned unmap requests to
fail. The only phrase I found in SPC-4 about unaligned unmap
requests is the following: "An unmap request with a starting LBA
that is not optimal may result in unmap operations on fewer LBAs
than requested." Hence check that unaligned unmap requests succeed.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>