UPSTREAM: f2fs: check zone write pointer points to the end of zone

We don't need to report an issue, when the zone write pointer already
points to the end of the zone, since the zone mismatch is already taken
care.

Change-Id: Ifc967abe44521cd239ebac509353c25e36cc7a18
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit c9667b19)