Revert "s390/qeth: fix using of ref counter for rxip addresses"

This reverts commit cb816192.

The issue this attempted to fix never actually occurs.
l3_add_rxip() checks (via l3_ip_from_hash()) if the requested address
was previously added to the card. If so, it returns -EEXIST and doesn't
call l3_add_ip().
As a result, the "address exists" path in l3_add_ip() is never taken
for rxip addresses, and this patch had no effect.

Fixes: cb816192 ("s390/qeth: fix using of ref counter for rxip addresses")
Signed-off-by: Julian Wiedmann <jwi@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>