libbpf: Clean up legacy bpf maps declaration in bpf_helpers

Legacy BPF map declarations are no longer supported in libbpf v1.0 [0].
Only BTF-defined maps are supported starting from v1.0, so it is time to
remove the definition of bpf_map_def in bpf_helpers.h.

  [0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0

Signed-off-by: Xin Liu <liuxin350@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20220913073643.19960-1-liuxin350@huawei.com

tools/lib/bpf/bpf_helpers.h

@@ -160,18 +160,6 @@ bpf_tail_call_static(void *ctx, const void *map, const __u32 slot)
 }
 #endif
 
-/*
- * Helper structure used by eBPF C program
- * to describe BPF map attributes to libbpf loader
- */
-struct bpf_map_def {
-	unsigned int type;
-	unsigned int key_size;
-	unsigned int value_size;
-	unsigned int max_entries;
-	unsigned int map_flags;
-} __attribute__((deprecated("use BTF-defined maps in .maps section")));
-
 enum libbpf_pin_type {
 	LIBBPF_PIN_NONE,
 	/* PIN_BY_NAME: pin maps by name (in /sys/fs/bpf by default) */