RDMA/hns: Fix refcount leak in hns_roce_mmap

rdma_user_mmap_entry_get_pgoff() takes the reference.
Add missing rdma_user_mmap_entry_put() to release the reference.

Fixes: 0045e0d3 ("RDMA/hns: Support direct wqe of userspace")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Acked-by Haoyue Xu <xuhaoyue1@hisilicon.com>
Link: https://lore.kernel.org/r/20221223072900.802728-1-linmq006@gmail.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/hw/hns/hns_roce_main.c

@@ -443,14 +443,15 @@ static int hns_roce_mmap(struct ib_ucontext *uctx, struct vm_area_struct *vma)
 		prot = pgprot_device(vma->vm_page_prot);
 		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
+		goto out;
 	}
 
 	ret = rdma_user_mmap_io(uctx, vma, pfn, rdma_entry->npages * PAGE_SIZE,
 				prot, rdma_entry);
 
+out:
 	rdma_user_mmap_entry_put(rdma_entry);
-
 	return ret;
 }