[source] tools: xz: force building without ccache

[LEDE Commits]

jow pushed a commit to source.git, branch master:
https://git.lede-project.org/27950ddc0e6069b64e40a8caf203b595a58f741b

commit 27950ddc0e6069b64e40a8caf203b595a58f741b
Author: Jo-Philipp Wich <jo at mein.io>
AuthorDate: Thu Oct 6 15:25:12 2016 +0200

    tools: xz: force building without ccache
    
    Since XZ is required to bootstrap ccache we must not use the ccache compiler
    wrapper to avoid circular dependencies.
    
    Signed-off-by: Jo-Philipp Wich <jo at mein.io>
---
 tools/xz/Makefile | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/xz/Makefile b/tools/xz/Makefile
index d08d6f8..45735e8 100644
--- a/tools/xz/Makefile
+++ b/tools/xz/Makefile
@@ -18,6 +18,9 @@ HOST_BUILD_PARALLEL:=1
 
 include $(INCLUDE_DIR)/host-build.mk
 
+HOSTCC := $(HOSTCC_NOCACHE)
+HOSTCXX := $(HOSTCXX_NOCACHE)
+
 HOST_CONFIGURE_ARGS += \
 	--enable-static=yes \
 	--enable-shared=no \