Fill in the appropriate limits to avoid inconsistencies
in the vfs cached inode times when timestamps are
outside the permitted range.

Also change the local_to_gmt() to use time64_t instead
of time32_t.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: Jeff Layton <jlayton@kernel.org>
Cc: mikulas@artax.karlin.mff.cuni.cz