pxa2xx_spi: prevent panic case setup() fails

setup() may fail before ctldata is set, causing a kernel panic on
cleanup().

Signed-off-by: Daniel Ribeiro <drwyrm@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Eric Miao <eric.y.miao@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/spi/pxa2xx_spi.c

@@ -1373,6 +1373,9 @@ static void cleanup(struct spi_device *spi)
 {
 	struct chip_data *chip = spi_get_ctldata(spi);
 
+	if (!chip)
+		return;
+
 	if (gpio_is_valid(chip->gpio_cs))
 		gpio_free(chip->gpio_cs);