[ARM] 5077/1: spi: fix list scan success verification in PXA ssp driver

The list search success check in arch/arm/mach-pxa/ssp.c is wrong: for
example, it didn't recognise failure for me when I requested port 0.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/ssp.c

@@ -330,7 +330,7 @@ struct ssp_device *ssp_request(int port, const char *label)
 
 	mutex_unlock(&ssp_lock);
 
-	if (ssp->port_id != port)
+	if (&ssp->node == &ssp_list)
 		return NULL;
 
 	return ssp;