LoongArch: BPF: Fix the tailcall hierarchy

In specific use cases combining tailcalls and BPF-to-BPF calls，
MAX_TAIL_CALL_CNT won't work because of missing tail_call_cnt
back-propagation from callee to caller. This patch fixes this
tailcall issue caused by abusing the tailcall in bpf2bpf feature
on LoongArch like the way of "bpf, x64: Fix tailcall hierarchy".

Push tail_call_cnt_ptr and tail_call_cnt into the stack,
tail_call_cnt_ptr is passed between tailcall and bpf2bpf,
uses tail_call_cnt_ptr to increment tail_call_cnt.

Fixes: bb035ef0 ("LoongArch: BPF: Support mixing bpf2bpf and tailcalls")
Reviewed-by: Geliang Tang <geliang@kernel.org>
Reviewed-by: Hengqi Chen <hengqi.chen@gmail.com>
Signed-off-by: Haoran Jiang <jianghaoran@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>