f2fs: remove unmatched zero_user_segment when convert inline dentry

f2fs: remove unmatched zero_user_segment when convert inline dentry

Since the layout of regular dentry block is different from inline dentry
block, zero_user_segment starting from MAX_INLINE_DATA(dir) is not
correct for regular dentry block, besides, bitmap is already copied and
used, so there is no necessary to zero page at all, so just remove the
zero_user_segment is OK.

Signed-off-by: Yunlong Song <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>