f2fs: remove the rw_flag domain from f2fs_io_info

When using the f2fs_io_info in the low level, we still need to merge the
rw and rw_flag, so use the rw to hold all the io flags directly,
and remove the rw_flag field.

ps.It is based on the previous patch:
f2fs: move all the bio initialization into __bio_alloc

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 9f8bdd0..555ae76 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -916,8 +916,7 @@
 {
 	struct f2fs_io_info fio = {
 		.type = META,
-		.rw = WRITE_SYNC,
-		.rw_flag = REQ_META | REQ_PRIO
+		.rw = WRITE_SYNC | REQ_META | REQ_PRIO
 	};
 
 	set_page_writeback(page);
@@ -931,7 +930,6 @@
 	struct f2fs_io_info fio = {
 		.type = NODE,
 		.rw = WRITE_SYNC,
-		.rw_flag = 0
 	};
 
 	set_summary(&sum, nid, 0, 0);
@@ -1018,7 +1016,6 @@
 	struct f2fs_io_info fio = {
 		.type = NODE,
 		.rw = WRITE_SYNC,
-		.rw_flag = 0
 	};
 
 	curseg = CURSEG_I(sbi, type);
@@ -1598,8 +1595,7 @@
 	int blkno = start;
 	struct f2fs_io_info fio = {
 		.type = META,
-		.rw = READ_SYNC,
-		.rw_flag = REQ_META | REQ_PRIO
+		.rw = READ_SYNC | REQ_META | REQ_PRIO
 	};
 
 	for (; blkno < start + nrpages && blkno < sit_blk_cnt; blkno++) {