Delete swap partition
You should be able to use a tool, such as a GParted Live CD, to delete the swap file partition and resize the OS X partition afterwards.

Per this Apple discussion forum that covered this topic:


  I believe that you can do it with a Live GParted CD. 
  
  http://gparted.sourceforge.net/livecd.php
  
  Boot with the Live CD in the drive and delete the swap partition. You
  may even be able to resize the OS X partition with GParted afterwards.


Alternately, back up all of your data and applications and wipe/repartition the main drive and install OS X from scratch. Takes a bit longer, but will give you a fresh OS X installation.