atm: idt77105: fix fetch_stats() result

copy_to_user() used PRIV(dev)->stats instead of local stats variable.
Zero stats were returned to user in case of (zero != 0), also memcpy()
was pointless.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: David S. Miller <davem@davemloft.net>