Before you do anything make sure you have a good backup because one wrong move here and your drive will not be bootable and all data will be gone. So don't blame me if this goes badly.
🙂
Okay... follow these steps.
First boot from the USB key then get into Terminal from the Utilities menu in recovery.
Enter this command to turn off core storage for the main volume so we can later resize it. It takes a bit to finish.
Now enter the following to unmount the disk.
Code:
diskutil unmountDisk /dev/disk0
Now these two one after the other to remove the 16.8 and 122.9MB little partitions you want gone.
Now you should be able to exit Terminal then use Disk Utility to expand the OS X volume to fill the disk.