mount-util: handle remount failures gracefully if flags already match
    
    In bind_remount_one_with_mountinfo() let's handle mount failures
    gracefully if the flags already match anyway. This isn't perfect, since
    it mixes up superblock and mount point flags, but it's close enough.
    
    (cherry picked from commit b23c6a6411fd58ac281642bcae915a7ea55db5c7)