smb: client: fix regression with native SMB symlinks

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix regression with native SMB symlinks Some users and customers reported that their backup/copy tools started to fail when the directory being copied contained symlink targets that the client couldn't parse - even when those symlinks weren't followed. Fix this by allowing lstat(2) and readlink(2) to succeed even when the client can't resolve the symlink target, restoring old behavior.