Sync up error codes
Sync up error codes

Instead of using a combo of SCSI status/sense, -Eyxz, and TCMU
defined error codes in the handler API and IO path define
a set of TCMU status codes that will be used.

Signed-off-by: Mike Christie <39daeb1549a929782e38aa87c4e3da7f3844b09a@redhat.com>

open-iscsi/tcmu-runner,open-iscsi/tcmu-runner,agrover/tcmu-runner