timestamp_truncate() is the replacement api for
timespec64_trunc. timestamp_truncate() additionally clamps
timestamps to make sure the timestamps lie within the
permitted range for the filesystem.
But, fat always truncates the times locally after it obtains
the timestamps from current_time().
Implement a local version here along the lines of existing
truncate functions.
Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Cc: hirofumi@mail.parknet.co.jp Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>