applied patch from Mike Hommey fixing distclean, fixes #520387 Daniel

* xstc/Makefile.am: applied patch from Mike Hommey fixing distclean,
  fixes #520387
Daniel

svn path=/trunk/; revision=3723
diff --git a/xstc/Makefile.am b/xstc/Makefile.am
index 2d24f02..966a8de 100644
--- a/xstc/Makefile.am
+++ b/xstc/Makefile.am
@@ -128,8 +128,5 @@
 	   echo '## Running the regression tests under Valgrind' ;	\
 	   $(MAKE) CHECKER='valgrind -q' MAKEFLAGS+=--silent pytests ; fi);
 
-clean:
-	rm -f $(PYSCRIPTS) test.log
+CLEANFILES=$(PYSCRIPTS) test.log
 
-distclean:
-	rm -rf $(PYSCRIPTS) test.log # TESTDIRS