f2fs: fix to parse temperature correctly in f2fs_get_segment_temp()

In __get_segment_type(), __get_segment_type_6() may return
CURSEG_COLD_DATA_PINNED or CURSEG_ALL_DATA_ATGC log type, but
following f2fs_get_segment_temp() can only handle persistent
log type, fix it.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>