Disk Rename in LVM

I installed ubuntu 14.04 with LVM, the disk name was showing properly as I had specified while installation till I performed apt-get updated && upgrade.

Before Upgrade

/dev/mapper/UBUNTU--VG01-UBUNTU--ROOT  37G  1.3G   34G   4% /
/dev/mapper/UBUNTU--VG01-UBUNTU--MNT   93G   60M   88G   1% /MNT

After Upgrade

/dev/dm-0  37G  1.3G   34G   4% /

but /mnt partition name remains as it is.

/dev/mapper/UBUNTU--VG01-UBUNTU--MNT   93G   60M   88G   1% /MNT

Now I need the name which I had specified while installation. How do I rename it.

Please help.