bpfilter: switch to CC from HOSTCC

check that CC can build executables and use that compiler instead of HOSTCC

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

scripts/cc-can-link.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+cat << "END" | $@ -x c - -o /dev/null >/dev/null 2>&1 && echo "y"
+#include <stdio.h>
+int main(void)
+{
+	printf("");
+	return 0;
+}
+END