IB/rxe: avoid double kfree skb

IB/rxe: avoid double kfree skb

In rxe_send, when network_type is not RDMA_NETWORK_IPV4 or
RDMA_NETWORK_IPV6, skb is freed and -EINVAL is returned.
Then rxe_xmit_packet will return -EINVAL, too. In rxe_requester,
this skb is double freed.
In rxe_requester, kfree_skb is needed only after fill_packet fails.
So kfree_skb is moved from label err to test fill_packet.

Fixes: 5793b4652155 ("IB/rxe: remove unnecessary skb_clone in xmit")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Zhu Yanjun <[email protected]>
Reviewed-by: Leon Romanovsky <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>