ext4: convert to new timestamp accessors

[ Upstream commit b898ab23 ]

Convert to using the new inode timestamp accessor functions.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-33-jlayton@kernel.org


Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: c7fc0366 ("ext4: partial zero eof block on unaligned inode size extension")
Signed-off-by: Sasha Levin <sashal@kernel.org>