iproute2: ensure TARGET_LDFLAGS are used

Otherwise we can end up with various linker issues (E.G. linking shared
against libc for a static build, ..).

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/iproute2/iproute2.mk

@@ -58,7 +58,7 @@ endef
 
 define IPROUTE2_BUILD_CMDS
 	$(SED) 's/$$(CCOPTS)//' $(@D)/netem/Makefile
-	$(TARGET_MAKE_ENV) $(MAKE) \
+	$(TARGET_MAKE_ENV) LDFLAGS="$(TARGET_LDFLAGS)" $(MAKE) \
 		DBM_INCLUDE="$(STAGING_DIR)/usr/include" \
 		CCOPTS="$(TARGET_CFLAGS) -D_GNU_SOURCE" \
 		SHARED_LIBS="$(if $(BR2_STATIC_LIBS),n,y)" -C $(@D)