kbuild: move tools_silent to a more relevant place

This would disturb the change the sub-make part. Move it near the
tools/ target.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Makefile

@@ -90,7 +90,6 @@ endif
 
 ifneq ($(findstring s,$(filter-out --%,$(MAKEFLAGS))),)
   quiet=silent_
-  tools_silent=s
 endif
 
 export quiet Q KBUILD_VERBOSE
@@ -1674,6 +1673,11 @@ image_name:
 	@echo $(KBUILD_IMAGE)
 
 # Clear a bunch of variables before executing the submake
+
+ifeq ($(quiet),silent_)
+tools_silent=s
+endif
+
 tools/: FORCE
 	$(Q)mkdir -p $(objtree)/tools
 	$(Q)$(MAKE) LDFLAGS= MAKEFLAGS="$(tools_silent) $(filter --j% -j,$(MAKEFLAGS))" O=$(abspath $(objtree)) subdir=tools -C $(src)/tools/