ext4: unlock xattr_sem properly in ext4_inline_data_truncate()

It takes xattr_sem to check inline data again but without unlock it
in case not have. So unlock it before return.

Fixes: aef1c851 ("ext4: let ext4_truncate handle inline data correctly")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://lore.kernel.org/r/1604370542-124630-1-git-send-email-joseph.qi@linux.alibaba.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org

fs/ext4/inline.c

@@ -1880,6 +1880,7 @@ int ext4_inline_data_truncate(struct inode *inode, int *has_inline)
 
 	ext4_write_lock_xattr(inode, &no_expand);
 	if (!ext4_has_inline_data(inode)) {
+		ext4_write_unlock_xattr(inode, &no_expand);
 		*has_inline = 0;
 		ext4_journal_stop(handle);
 		return 0;