spi: omap2-mcspi: Fix the error handling in probe

The kfree() is taken care of by the spi core (spi_master_release() function)
that is called once the last reference to the underlying struct device has
been released. So the driver need not call kfree.

Also the put was missed in some of the error handling fix the same.
There by fixing the missing device_put in some of the error paths.

Acked-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>