[U-Boot] [PATCH v2] Pass empty CFLAGS on invocation of libfdt/setup.py

[Max Filippov]

When building u-boot tools in cross-build environment CFLAGS environment
variable set up for target is taken into an account when building code
for host. Make it empty on invocation of python.

This fixes the following build errors when cross-compiling for xtensa:

  cc1: error: unrecognized command line option "-mlongcalls"
  cc1: error: unrecognized command line option "-mauto-litpools"

Signed-off-by: Max Filippov <jcmvbkbc at gmail.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
Changes v1->v2:
- remove "" after CFLAGS=

 tools/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/Makefile b/tools/Makefile
index 1c840d7..f3de657 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -120,7 +120,7 @@ _libfdt.so-sharedobjs += $(LIBFDT_OBJS)
 libfdt:
 
 tools/_libfdt.so: $(patsubst %.o,%.c,$(LIBFDT_OBJS)) tools/libfdt_wrap.c
-	LDFLAGS="$(HOSTLDFLAGS)" python $(srctree)/lib/libfdt/setup.py \
+	LDFLAGS="$(HOSTLDFLAGS)" CFLAGS= python $(srctree)/lib/libfdt/setup.py \
 		"$(_hostc_flags)" $^
 	mv _libfdt.so $@
 
-- 
2.1.4