Current code tries to derive VLAN ID and compares it with GID
attribute for matching entry. This raw search fails on macvlan
netdevice as its not a VLAN device, but its an upper device of a VLAN
netdevice.

Due to this limitation, incoming QP1 packets fail to match in the
GID table. Such packets are dropped.

Hence, to support it, use the existing rdma_read_gid_l2_fields()
that takes care of diffferent device types.

Fixes: dbf727de ("IB/core: Use GID table in AH creation and dmac resolution")
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Link: https://lore.kernel.org/r/20191002121750.17313-1-leon@kernel.orgSigned-off-by: Doug Ledford <dledford@redhat.com>