[S390] cio: handle ssch() return codes correctly.

ssch() has two classes of return codes:
- condition codes (0-3) which need to be translated to Linux
  error codes
- Linux error codes (-EIO on exceptions) which should be passed
  to the caller (instead of erronously being handled like
  condition code 3)
Signed-off-by: NCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

drivers/s390/cio/cio.c

@@ -208,8 +208,10 @@ cio_start_key (struct subchannel *sch,	/* subchannel structure */
 	case 1:		/* status pending */
 	case 2:		/* busy */
 		return -EBUSY;
-	default:		/* device/path not operational */
+	case 3:		/* device/path not operational */
 		return cio_start_handle_notoper(sch, lpm);
+	default:
+		return ccode;
 	}
 }