[openwrt/openwrt] tools/fakeroot: explicitly pass CPP variable

[LEDE Commits]

nbd pushed a commit to openwrt/openwrt.git, branch openwrt-21.02:
https://git.openwrt.org/83bf22ba2e5853a5afc09585f76dc76c0d74ebea

commit 83bf22ba2e5853a5afc09585f76dc76c0d74ebea
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Wed Oct 13 16:36:16 2021 +0200

    tools/fakeroot: explicitly pass CPP variable
    
    For some reason, the generated configure script fails to properly set up
    the internal preprocessor command variable, causing the host OS check for
    Darwin to fail after the last update.
    Explicitly setting CPP fixes this issue
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
    (cherry-picked from commit 48e209e5c5a76dd0ce4a2a8b014416dc988269a3)
---
 tools/fakeroot/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/fakeroot/Makefile b/tools/fakeroot/Makefile
index e9daa4b6ad..5f10070eac 100644
--- a/tools/fakeroot/Makefile
+++ b/tools/fakeroot/Makefile
@@ -19,7 +19,8 @@ include $(INCLUDE_DIR)/host-build.mk
 
 HOST_CONFIGURE_VARS += \
 	ac_cv_header_sys_capability_h=no \
-	ac_cv_func_capset=no
+	ac_cv_func_capset=no \
+	CPP="$(HOSTCC) -E"
 
 HOST_CONFIGURE_ARGS += \
 	--with-ipc=tcp