build: for cmake, always use ccache from staging dir instead of relying on the host

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48079

include/cmake.mk

@@ -18,10 +18,7 @@ ifeq ($(CONFIG_CCACHE),)
  CMAKE_C_COMPILER_ARG1:=
  CMAKE_CXX_COMPILER_ARG1:=
 else
-  CCACHE:=$(shell which ccache)
-  ifeq ($(CCACHE),)
-    CCACHE:=$(STAGING_DIR_HOST)/bin/ccache
-  endif
+  CCACHE:=$(STAGING_DIR_HOST)/bin/ccache
   CMAKE_C_COMPILER:=$(CCACHE)
   CMAKE_C_COMPILER_ARG1:=$(TARGET_CC_NOCACHE)
   CMAKE_CXX_COMPILER:=$(CCACHE)