RDMA/rxe: For invalidate compare according to set keys in mr

RDMA/rxe: For invalidate compare according to set keys in mr

[ Upstream commit 174e7b137042f19b5ce88beb4fc0ff4ec6b0c72a ]

The 'rkey' input can be an lkey or rkey, and in rxe the lkey or rkey have
the same value, including the variant bits.

So, if mr->rkey is set, compare the invalidate key with it, otherwise
compare with the mr->lkey.

Since we already did a lookup on the non-varient bits to get this far, the
check's only purpose is to confirm that the wqe has the correct variant
bits.

Fixes: 001345339f4c ("RDMA/rxe: Separate HW and SW l/rkeys")
Link: https://lore.kernel.org/r/20220707073006.328737-1-haris.phnx@gmail.com
Signed-off-by: Md Haris Iqbal <haris.phnx@gmail.com>
Reviewed-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>