Get rid of lingering partition
I would use the terminal to sort things out if you don't see what's happened in Disk Utility.

diskutil list


From there, you can see all the names and numbers OS X has given to the volumes/partitions. Eject them all (except for the booted OS). diskutil eject disk2s2 etc...

At that point, you might need to clean up the bad mount points.

ls -l /Volumes


At this point you want to be sure you're not deleting actual files so if you're not comfortable using rm in terminal, you can use the Finder. Use the Go menu to Go to Folder... and enter /Volumes

Rename the Macintosh HD to something like temp and then move all the bad mount points to the trash and rename your boot volume to be what you wish. Now when you mount the drives the name should match what you have in Disk Utility.