criu/Makefile: fix criu/arch/* rebuild

Problem: if we do

 touch criu/arch/x86/cpu.c

nothing is being rebuilt.

For detailed analisys, see the previous commit
("criu/Makefile: fix rebuilding criu/pie/pie.lib.a").

Note there are other targets in criu/Makefile where one
might want to add .FORCE to, but it's not needed as they
all depend on another target which itself is marked as .PHONY.

travis-ci: success for Makefiles: fix deps checking
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Reviewed-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/Makefile

@@ -44,7 +44,7 @@ include $(SRC_DIR)/criu/Makefile.packages
 #
 # Architecture dependent part.
 ARCH-LIB		:= $(ARCH_DIR)/crtools.built-in.o
-$(ARCH-LIB):
+$(ARCH-LIB): .FORCE
 	$(Q) $(MAKE) $(build)=$(ARCH_DIR) all
 
 #