RDMA/rtrs-clt: Correct the checking of ib_map_mr_sg

We should check with count, also the only successful case is that
all sg elements are mapped, so make it explicitly.
Acked-by: Jack Wang <jinpu.wang@ionos.com>
Signed-off-by: Guoqing Jiang <guoqing.jiang@linux.dev>
Link: https://lore.kernel.org/r/20221117101945.6317-5-guoqing.jiang@linux.devSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/ulp/rtrs/rtrs-clt.c

@@ -1064,10 +1064,8 @@ static int rtrs_map_sg_fr(struct rtrs_clt_io_req *req, size_t count)
 
 	/* Align the MR to a 4K page size to match the block virt boundary */
 	nr = ib_map_mr_sg(req->mr, req->sglist, count, NULL, SZ_4K);
-	if (nr < 0)
-		return nr;
-	if (nr < req->sg_cnt)
-		return -EINVAL;
+	if (nr != count)
+		return nr < 0 ? nr : -EINVAL;
 	ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));
 
 	return nr;