This is the same change as the previous commit, but for scatter abds.
Its less clear if this change is needed. Since scatter abds are only
ever added a page at time, both sides of the split should always be
added in consecutive segments.
Intuitively though, it may be possible for a partially-filled bio to be
used, or a bio with an odd number of iovecs, and that then could lead to
a misaligned bio. While I've not been able to reproduce this at all, it
seems to make sense to protect against it.
Signed-off-by: Rob Norris <rob.norris@klarasystems.com>
(cherry picked from commit cbdf21fd1a32a5e696a22cad497d9211221fa309)