iscsi: partly avoid iovec linearization in iscsi_aio_writev libiscsi expects all write16 data in a linear buffer. If the iovec only contains one buffer we can skip the linearization step as well as the additional malloc/free and pass the buffer directly. Reported-by: Ronnie Sahlberg <ronniesahlberg@gmail.com> Signed-off-by: Peter Lieven <pl@kamp.de> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>