SCSI: fix regression in scsi_send_eh_cmnd()

Commit ac61d195 (scsi: set correct completion code in
scsi_send_eh_cmnd()) introduced a bug.  It changed the stored return
value from a queuecommand call, but it didn't take into account that
the return value was used again later on.  This patch fixes the bug by
changing the later usage.

There is a big comment in the middle of scsi_send_eh_cmnd() which
does a good job of explaining how the routine works.  But it mentions
a "rtn = FAILURE" value that doesn't exist in the code.  This patch
adjusts the code to match the comment (I assume the comment is right
and the code is wrong).

This fixes Bugzilla #88341.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Андрей Аладьев <aladjev.andrew@gmail.com>
Tested-by: Андрей Аладьев <aladjev.andrew@gmail.com>
Fixes: ac61d195
Acked-by: Hannes Reinecke <hare@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>