BugLink: http://bugs.launchpad.net/bugs/1646204

Instead of using -ERROR-style returns, use sense_reason_t. This lets us
remove tcmu_pass_op(), and return more correct sense values.
Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Christie <mchristi@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
(cherry picked from linux-next commit 02eb924f)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>