f2fs: avoid using native allocate_segment_by_default()

[ Upstream commit 509f1010 ]

As we did for other cases, in fix_curseg_write_pointer(), let's
use wrapped f2fs_allocate_new_section() instead of native
allocate_segment_by_default(), by this way, it fixes to cover
segment allocation with curseg_lock and sentry_lock.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: 43563069 ("f2fs: check curseg->inited before write_sum_page in change_curseg")
Signed-off-by: Sasha Levin <sashal@kernel.org>