[SCSI] add DID_TARGET_FAILURE and DID_NEXUS_FAILURE to hostbyte_table in constants.c

Without this patch, scsi_show_result prints hostbyte as invalid for statuses
that are not defined in hostbyte_table (when scsi logging is enabled).

Signed-off-by: Babu Moger <babu.moger@netapp.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>