usb: musb: core: Call dma_controller_destroy() in error path only once.

In commit f3ce4d5b

 ("usb: musb: core: call dma_controller_destroy() in the err path")
I erroneously assumed that the dma controller is not removed in the
error patch. This was wrong because it happens later via musb_free().
That means the original commit can be reverted because it is wrong or we
do this, so it is more obvious.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>