Add support for signed 8-bit attribute helpers in nl80211 driver for compatibility with older libnl versions

src/drivers/driver_nl80211.c

@@ -66,6 +66,14 @@ enum nlmsgerr_attrs {
 #ifndef SOL_NETLINK
 #define SOL_NETLINK 270
 #endif
+#ifndef NLA_S8
+/* libnl < 3.3 does not define signed 8-bit attr helpers */
+#define NLA_S8 NLA_U8
+static inline s8 nla_get_s8(const struct nlattr *nla)
+{
+	return (s8) nla_get_u8(nla);
+}
+#endif /* NLA_S8 */
 
 
 #ifdef ANDROID