spi: spi_device memory should be released instead of device.

The memory for dev variable is allocated as a part of
spi_device structure memory which the dev belongs to.
Thus when the memory is released the right pointer is used.

Signed-off-by: Roman Tereshonkov <[e-mail]>
Signed-off-by: Grant Likely <[e-mail]>

drivers/spi/spi.c

···
 		spi->master->cleanup(spi);
 
 	spi_master_put(spi->master);
-	kfree(dev);
+	kfree(spi);
 }
 
 static ssize_t