bpf: libbpf: fix memleak by freeing line_info

This patch fixes a memory leak in libbpf by freeing up line_info
member of struct bpf_program while unloading a program.

Fixes: 3d650141 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: NPrashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Acked-by: NMartin KaFai Lau <kafai@fb.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

tools/lib/bpf/libbpf.c

@@ -266,6 +266,7 @@ void bpf_program__unload(struct bpf_program *prog)
 
 	zclose(prog->btf_fd);
 	zfree(&prog->func_info);
+	zfree(&prog->line_info);
 }
 
 static void bpf_program__exit(struct bpf_program *prog)