cifs: use the expiry output of dns_query to schedule next resolution

cifs: use the expiry output of dns_query to schedule next resolution

BugLink: https://bugs.launchpad.net/bugs/1954926
We recently fixed DNS resolution of the server hostname during reconnect.
However, server IP address may change, even when the old one continues
to server (although sub-optimally).

We should schedule the next DNS resolution based on the TTL of
the DNS record used for the last resolution. This way, we resolve the
server hostname again when a DNS record expires.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: <stable@vger.kernel.org> # v5.11+
Signed-off-by: Steve French <stfrench@microsoft.com>
(backported from commit 506c1da44fee32ba1d3a70413289ad58c772bba6)
[rtg - dropped changes to fs/cifs/misc.c]
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>