cxgb4: fix the error path of cxgb4_uld_register()

On multi adapter setup if the uld registration fails even on
one adapter, the allocated resources for the uld on all the
adapters are freed, rendering the functioning adapters unusable.

This commit fixes the issue by freeing the allocated resources
only for the failed adapter.

Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>