samples/bpf: add map_flags to bpf loader

note old loader is compatible with new kernel.
map_flags are optional

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h
index 811bcca..9363500 100644
--- a/samples/bpf/bpf_helpers.h
+++ b/samples/bpf/bpf_helpers.h
@@ -61,6 +61,7 @@
 	unsigned int key_size;
 	unsigned int value_size;
 	unsigned int max_entries;
+	unsigned int map_flags;
 };
 
 static int (*bpf_skb_store_bytes)(void *ctx, int off, void *from, int len, int flags) =