fixed a stupid error in snc Makefile

src/snc/Makefile

@@ -50,8 +50,8 @@ snl.c: snl.lem snl.lt $(LEMON)
 	$(RM) snl.c snl.h
 	$(LEMON) o=. $<
 
-snl.h: snl.c
-	# empty recipy needed to work around make bug #35455
+# empty recipy needed to work around make bug #35455
+snl.h: snl.c ;
 
 vpath %.re ..
 
@@ -59,7 +59,7 @@ lexer.c: snl.re
 	$(RE2C) -s -b -o $@ $<
 
 # work around bug in base rules
-lexer.o: snl.h
+lexer$(OBJ): snl.h
 
 $(COMMON_DIR)/snl.bnf: snl.lem
 	$(RM) $@