[SCSI] libiscsi: return error passed in during iscsi recovery

Due to patch building error on my side, we are still passing DID_BUS_BUSY
for commands that are running, when we want to return whatever the caller
of fail_all_commands wanted. This replaces the hardcoded error code with
the value that is passed in.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>