This patch adds support for spdk_bdev_readv in scsi layer.
It also fixes write so that it uses multiple iov's instead of one.
Currently we should use only task->iov (for single vector operation)
or task->iovs (for multiple vector operations).
Signed-off-by: Piotr Pelplinski <piotr.pelplinski@intel.com>
Change-Id: Ia3b2f6d18fd212b11d7b63b11dc46ec5bbc74788
