scsi: NCR5380: Unconditionally clear ICR after do_abort()

When do_abort() succeeds, the target will go to BUS FREE phase and there
will be no connected command. Therefore, that function should clear the
Initiator Command Register before returning. It already does so in case of
NCR5380_poll_politely() failure; do the same for the other error case too,
that is, NCR5380_transfer_pio() failure.

Cc: Michael Schmitz <schmitzmic@gmail.com>
Cc: Ondrej Zary <linux@zary.sk>
Link: https://lore.kernel.org/r/4277b28ee2551f884aefa85965ef3c498344f301.1573875417.git.fthain@telegraphics.com.au


Reviewed-and-tested-by: Michael Schmitz <schmitzmic@gmail.com>
Tested-by: Ondrej Zary <linux@zary.sk>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>