fs: f2fs: use ktime_get_real_seconds for sit_info times

fs: f2fs: use ktime_get_real_seconds for sit_info times

CURRENT_TIME_SEC is not y2038 safe.

Replace use of CURRENT_TIME_SEC with ktime_get_real_seconds in segment
timestamps used by GC algorithm including the segment mtime timestamps.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Deepa Dinamani <[email protected]>
Reviewed-by: Arnd Bergmann <[email protected]>
Cc: Jaegeuk Kim <[email protected]>
Cc: Chao Yu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>