client: convert to new timestamp accessors

[ Upstream commit 8f22ce70

 ]

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-66-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: 01fe654f

 ("fs: cifs: Fix atime update check")
Signed-off-by: Sasha Levin <sashal@kernel.org>