ext4_journal: flush dirty buffers which have BC_TMP flag set.

lwext4/ext4_bcache.c

@@ -281,7 +281,8 @@ int ext4_bcache_free(struct ext4_bcache *bc, struct ext4_block *b)
 		if (ext4_bcache_test_flag(buf, BC_DIRTY) &&
 		    ext4_bcache_test_flag(buf, BC_UPTODATE)) {
 			if (bc->bdev->cache_write_back &&
-			    !ext4_bcache_test_flag(buf, BC_FLUSH))
+			    !ext4_bcache_test_flag(buf, BC_FLUSH) &&
+			    !ext4_bcache_test_flag(buf, BC_TMP))
 				ext4_bcache_insert_dirty_node(bc, buf);
 			else {
 				ext4_block_flush_buf(bc->bdev, buf);