EDIT: managed to reformat the partition to JHFS+, after accidentaly creating another partition i merged the new and the old one i dint want, then it let me merge all of them together.
I created a partition to originally use for linux. I gave it 30 GB and installed Linux no problem. Now I am in need for space in El Capitan and I can not remove the partition to give me more space. I managed to reformat it to HFS+ and it is not a corestorage(?) unit.
Here are screenshots of Disk Utility and the output of