[SCSI] zfcp: Pass return code from fc_block_scsi_eh to scsi eh

The return code FAST_IO_FAIL from fc_block_scsi_eh indicates that the
pending I/O requests have been terminated as a result of the
fast_io_fail_tmo. Pass this return code back to the scsi eh to stop
the scsi eh in this case.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>