RDMA/core: Fix user CQ creation for drivers without create_cq

CQ creation is failing for drivers that only implement create_user_cq
(e.g. EFA), when buffer isn't provided by userspace. This because of a
leftover check that requires create_cq existence in such case.

Remove the create_cq existence check from the no-buffer path. The
buffer is optional and drivers that handle their own memory should work
through create_user_cq regardless.

Fixes: 584ec74 ("RDMA/core: Prepare create CQ path for API unification")
Link: https://patch.msgid.link/r/[email protected]
Signed-off-by: Michael Margolin <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>

Author: mrgolin

drivers/infiniband/core/uverbs_std_types_cq.c

@@ -172,8 +172,7 @@ static int UVERBS_HANDLER(UVERBS_METHOD_CQ_CREATE)(
 		}
 		umem = &umem_dmabuf->umem;
 	} else if (uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_OFFSET) ||
-		   uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH) ||
-		   !ib_dev->ops.create_cq) {
+		   uverbs_attr_is_valid(attrs, UVERBS_ATTR_CREATE_CQ_BUFFER_LENGTH)) {
 		ret = -EINVAL;
 		goto err_event_file;
 	}