testing: Don't run tests when building tkm

The problem with XML/Ada described in 9c2aba27 actually occurs when
running the tests here.

Really fixes #336.

testing/scripts/recipes/010_tkm.mk

@@ -14,7 +14,7 @@ all: install
 	@touch $@
 
 .$(PKG)-built: .$(PKG)-cloned
-	cd $(PKG) && make tests && make
+	cd $(PKG) && make
 	@touch $@
 
 install: .$(PKG)-built