$(KBUILD_EXTRA_SYMBOLS) is not only used at compile time but also at link
time. Move the $(KBUILD_EXTRA_SYMBOLS) definitions such that it is
available both at compile time and at link time.
git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@9000 d57e44dd-8a1f-0410-8b47-8ef2f437770f