Fix parallel make targets

my last patch here fixed a missing dependency, but in the wrong
way.  It would build some object files twice, which could race.
The lib/all target already builds both libtcc{,b}1.a libs, so
a simple dependency is enough.

Makefile

@@ -250,8 +250,7 @@ libtcc1.a : tcc$(EXESUF) FORCE
 	@$(MAKE) -C lib DEFINES='$(DEF-$*)' CROSS_TARGET=$*
 
 # TinyCC runtime libraries
-libtccb1.a : tcc$(EXESUF) FORCE
-	@$(MAKE) -C lib DEFINES='$(DEF-$T)'
+libtccb1.a : libtcc1.a
 
 # Cross libtcc1.a
 %-libtccb1.a : %-tcc$(EXESUF) FORCE