IB/uverbs: Don't decrement usecnt on error paths

In error paths when destroying an object, uverbs should not decrement
associated objects' usecnt, since ib_dereg_mr(), ib_destroy_qp(),
etc. already do that.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/core/uverbs_cmd.c

@@ -492,7 +492,6 @@ err_idr:
 
 err_unreg:
 	ib_dereg_mr(mr);
-	atomic_dec(&pd->usecnt);
 
 err_up:
 	mutex_unlock(&ib_uverbs_idr_mutex);
@@ -986,11 +985,6 @@ err_idr:
 
 err_destroy:
 	ib_destroy_qp(qp);
-	atomic_dec(&pd->usecnt);
-	atomic_dec(&attr.send_cq->usecnt);
-	atomic_dec(&attr.recv_cq->usecnt);
-	if (attr.srq)
-		atomic_dec(&attr.srq->usecnt);
 
 err_up:
 	mutex_unlock(&ib_uverbs_idr_mutex);
@@ -1888,7 +1882,6 @@ err_idr:
 
 err_destroy:
 	ib_destroy_srq(srq);
-	atomic_dec(&pd->usecnt);
 
 err_up:
 	mutex_unlock(&ib_uverbs_idr_mutex);