atm: zatm: Fix an error handling path in 'zatm_init_one()'

If 'dma_set_mask_and_coherent()' fails, we must undo the previous
'pci_request_regions()' call.
Adjust corresponding 'goto' to jump at the right place of the error
handling path.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>