SCSI: spi_transport set_signalling is buggy

From: 	Matthew Wilcox <matthew@wil.cx>

Looks like you got the test backwards.  It would only call set_signalling
if type was SPI_SIGNAL_UNKNOWN.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_spi.c

@@ -361,9 +361,8 @@ static ssize_t store_spi_host_signalling(struct class_device *cdev,
 	enum spi_signal_type type = spi_signal_to_value(buf);
 
 	if (type != SPI_SIGNAL_UNKNOWN)
-		return count;
+		i->f->set_signalling(shost, type);
 
-	i->f->set_signalling(shost, type);
 	return count;
 }
 static CLASS_DEVICE_ATTR(signalling, S_IRUGO | S_IWUSR,