[PATCH] ipvs: use div_s64 for signed division

[Arnd Bergmann <arnd@xxxxxxxxxx>]

From: Arnd Bergmann <arnd@xxxxxxxx>

do_div() is only well-behaved for positive numbers, and now warns
when the first argument is a an s64:

net/netfilter/ipvs/ip_vs_est.c: In function 'ip_vs_est_calc_limits':
include/asm-generic/div64.h:222:35: error: comparison of distinct pointer types 
lacks a cast [-Werror]
  222 |         (void)(((typeof((n)) *)0) == ((uint64_t *)0));  \
      |                                   ^~
net/netfilter/ipvs/ip_vs_est.c:694:17: note: in expansion of macro 'do_div'
  694 |                 do_div(val, loops);

Convert to using the more appropriate div_s64(), which also
simplifies the code a bit.

Fixes: 705dd3444081 ("ipvs: use kthreads for stats estimation")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
 net/netfilter/ipvs/ip_vs_est.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/netfilter/ipvs/ip_vs_est.c b/net/netfilter/ipvs/ip_vs_est.c
index ce2a1549b304..dbc32f8cf1f9 100644
--- a/net/netfilter/ipvs/ip_vs_est.c
+++ b/net/netfilter/ipvs/ip_vs_est.c
@@ -691,15 +691,13 @@ static int ip_vs_est_calc_limits(struct netns_ipvs *ipvs, 
int *chain_max)
                }
                if (diff >= NSEC_PER_SEC)
                        continue;
-               val = diff;
-               do_div(val, loops);
+               val = div_s64(diff, loops);
                if (!min_est || val < min_est) {
                        min_est = val;
                        /* goal: 95usec per chain */
                        val = 95 * NSEC_PER_USEC;
                        if (val >= min_est) {
-                               do_div(val, min_est);
-                               max = (int)val;
+                               max = div_s64(val, min_est);
                        } else {
                                max = 1;
                        }
-- 
2.35.1