f2fs: use correct flag in f2fs_map_blocks()

We introduce F2FS_GET_BLOCK_READ in commit e2b4e2bc8865 ("f2fs: fix
incorrect mapping for bmap"), but forget to use this flag in the right
place, fix it.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index d265401..bc04e92 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -920,7 +920,8 @@
 			map.m_lblk = block_in_file;
 			map.m_len = last_block - block_in_file;
 
-			if (f2fs_map_blocks(inode, &map, 0, false))
+			if (f2fs_map_blocks(inode, &map, 0,
+							F2FS_GET_BLOCK_READ))
 				goto set_error_page;
 		}
 got_it: