dm9000: fix "BUG: spinlock recursion"

dm9000_set_rx_csum and dm9000_hash_table are called from atomic context (in
dm9000_init_dm9000), and from non-atomic context (via ethtool_ops and
net_device_ops respectively). This causes a spinlock recursion BUG. Fix this by
renaming these functions to *_unlocked for the atomic context, and make the
original functions locking wrappers for use in the non-atomic context.

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>