IB/core: Honor port_num while resolving GID for IB link layer

IB/core: Honor port_num while resolving GID for IB link layer

[ Upstream commit 563c4ba3bd2b8b0b21c65669ec2226b1cfa1138b ]

ah_attr contains the port number to which cm_id is bound. However, while
searching for GID table for matching GID entry, the port number is
ignored.

This could cause the wrong GID to be used when the ah_attr is converted to
an AH.

Reviewed-by: Daniel Jurgens <danielj@mellanox.com>
Signed-off-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>