bpf: Fix memleak in aux->func_info and aux->btf

The aux->func_info and aux->btf are leaked in the error out cases
during bpf_prog_load().  This patch fixes it.

Fixes: ba64e7d8

 ("bpf: btf: support proper non-jit func info")
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>