[openwrt/openwrt] build: use CCACHE_DIR for ccache directory

[LEDE Commits]

aparcar pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/01653fe3c765c88af23de650aebff2768dbecc32

commit 01653fe3c765c88af23de650aebff2768dbecc32
Author: Sven Wegener <sven.wegener at stealer.net>
AuthorDate: Fri Jan 1 11:43:50 2021 +0100

    build: use CCACHE_DIR for ccache directory
    
    It is being set by rules.mk with the same expression.
    
    Signed-off-by: Sven Wegener <sven.wegener at stealer.net>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 24f5955c90..4ccbc20b85 100644
--- a/Makefile
+++ b/Makefile
@@ -64,7 +64,7 @@ dirclean: clean
 
 cacheclean:
 ifneq ($(CONFIG_CCACHE),)
-	rm -rf $(if $(call qstrip,$(CONFIG_CCACHE_DIR)),$(call qstrip,$(CONFIG_CCACHE_DIR)),$(TOPDIR)/.ccache)
+	rm -rf $(CCACHE_DIR)
 endif
 
 ifndef DUMP_TARGET_DB