During a code scan for another change I discovered that this call to
pcnet32_free_ring must be removed.  If the open fails due to a lack of
memory all the ring structures are removed via the call to free_ring
and a subsequent call to open will dereference a null pointer in
pcnet32_init_ring.

Please apply to 2.6.17.
Signed-off-by: Don Fry <brazilnut@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>