[source] cmake: properly pass host cflags/ldflags to the build

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/6f9011f089981776970ca3fb397c483e257f9dde

commit 6f9011f089981776970ca3fb397c483e257f9dde
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Thu Jan 12 14:41:01 2017 +0100

    cmake: properly pass host cflags/ldflags to the build
    
    This should hopefully fix build issues where libraries that we ship in
    tools/ were accidentally picked up from other places on the system, e.g.
    /usr/local
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 tools/cmake/Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/cmake/Makefile b/tools/cmake/Makefile
index 08e5a69..f371239 100644
--- a/tools/cmake/Makefile
+++ b/tools/cmake/Makefile
@@ -24,7 +24,8 @@ HOST_CONFIGURE_CMD := \
 	$(BASH) ./configure \
 		$(if $(MAKE_JOBSERVER),--parallel="$(MAKE_JOBSERVER)")
 
-HOST_CONFIGURE_VARS :=
+HOST_CONFIGURE_VARS += \
+	CXXFLAGS="$(HOST_CFLAGS)"
 
 HOST_CONFIGURE_ARGS := \
 	--prefix=$(STAGING_DIR_HOST)