ucc_geth: Cleanup repetitive ucc_geth_memclean() calls

No need to call ucc_geth_memclean() so many times, just check for
errors in ucc_geth_open(), and call ucc_geth_stop() in case of errors.

The ucc_geth_stop() may be called anytime and will do the right thing.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>