IPoIB: Make sure struct ipoib_neigh.queue is always initialized
Move the initialization of ipoib_neigh's skb_queue into
ipoib_neigh_alloc(), since commit
2745b5b7 ("IPoIB: Fix skb leak when
freeing neighbour") will make iterate over the skb_queue to free any
packets left over when freeing the ipoib_neigh structure.
This fixes a crash when freeing ipoib_neigh structures allocated in
ipoib_mcast_send(), which otherwise don't have their skb_queue
initialized.
Signed-off-by: Roland Dreier <rolandd@cisco.com>