RDMA/mthca: Fix crash when polling CQ for shared QPs

Commit 21c2fe94 ("RDMA/mthca: Combine special QP struct with mthca QP")
introduced a new struct mthca_sqp which doesn't contain struct mthca_qp
any longer. Placing a pointer of this new struct into qptable leads
to crashes, because mthca_poll_one() expects a qp pointer. Fix this
by putting the correct pointer into qptable.

Fixes: 21c2fe94 ("RDMA/mthca: Combine special QP struct with mthca QP")
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Link: https://lore.kernel.org/r/20230713141658.9426-1-tbogendoerfer@suse.de


Signed-off-by: Leon Romanovsky <leon@kernel.org>