RDMA/rtrs: Fix clt_path::max_pages_per_mr calculation

If device max_mr_size bits in the range [mr_page_shift+31:mr_page_shift]
are zero, the `min3` function will set clt_path::max_pages_per_mr to
zero.

`alloc_path_reqs` will pass zero, which is invalid, as the third parameter
to `ib_alloc_mr`.

Fixes: 6a98d71 ("RDMA/rtrs: client: main functionality")
Signed-off-by: Honggang LI <honggangli@163.com>
Link: https://patch.msgid.link/20251229025617.13241-1-honggangli@163.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: Honggang-LI

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

@@ -1464,6 +1464,7 @@ static void query_fast_reg_mode(struct rtrs_clt_path *clt_path)
 	mr_page_shift      = max(12, ffs(ib_dev->attrs.page_size_cap) - 1);
 	max_pages_per_mr   = ib_dev->attrs.max_mr_size;
 	do_div(max_pages_per_mr, (1ull << mr_page_shift));
+	max_pages_per_mr = min_not_zero((u32)max_pages_per_mr, U32_MAX);
 	clt_path->max_pages_per_mr =
 		min3(clt_path->max_pages_per_mr, (u32)max_pages_per_mr,
 		     ib_dev->attrs.max_fast_reg_page_list_len);