ext4: Convert more i_flags references to use accessor functions

These changes are not ones which are likely to result in races, but
they should be fixed.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 6f3a27e..1765c2c 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -376,7 +376,7 @@
 	 * We have the extent map build with the tmp inode.
 	 * Now copy the i_data across
 	 */
-	ei->i_flags |= EXT4_EXTENTS_FL;
+	ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS);
 	memcpy(ei->i_data, tmp_ei->i_data, sizeof(ei->i_data));
 
 	/*