codegen: Fix memory leak when chaining up in fundamental classes
codegen: Fix memory leak when chaining up in fundamental classes

Fixes bug 684776.

spidermonkdust/vala,Distrotech/vala,GNOME/vala,GNOME/vala,rvu95/vala,GNOME/vala,spidermonkdust/vala,rvu95/vala,flobrosch/vala-fixes,severinh/vala,flobrosch/vala-fixes,frida/vala,rvu95/vala,frida/vala,xdave/pvala,playya/vala,Distrotech/vala,severinh/vala,frida/vala,spidermonkdust/vala,frida/vala,severinh/vala,playya/vala,GNOME/vala,Distrotech/vala,frida/vala,playya/vala,flobrosch/vala-fixes