staging: ozwpan: Revert last changes

staging: ozwpan: Revert last changes

This patch reverts the changes made by the following patches:

commit id: edea341b0477ce5d53f7341f8b8cf8c91ad54ecf
[PATCH 1/4] ozwpan: replace alloc_skb with dev_alloc_skb in ozpd.c

commit id: b59983f525396a47cf8b28c13bbd5d5ff57859b8
[PATCH 2/4] ozwpan: replace alloc_skb with dev_alloc_skb in ozproto.c

commit id: 4422a6c14d0d0bfe519ec487693f1787f64b0b90
[PATCH 3/4] ozwpan: replace kfree_skb with dev_kfree_skb in ozpd.c

commit id: e241a8b61671b487e1a04b455dbd32ab965250ef
[PATCH 4/4] ozwpan: replace kfree_skb with dev_kfree_skb in ozproto.c

The reason of this revert is that dev_alloc_skb() is not defined
to be used in the allocation of socket buffers on the transmit path
but on the receive path.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>