net/s2io: set_rxd_buffer_pointer returns -ENOMEM, not ENOMEM

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Cc: Ramkrishna Vepa <ram.vepa@neterion.com>
Cc: Rastapur Santosh <santosh.rastapur@neterion.com>
Cc: Sivakumar Subramani <sivakumar.subramani@neterion.com>
Cc: Sreenivasa Honnur <sreenivasa.honnur@neterion.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>