LoongArch: BPF: Adjust the jump offset of tail calls

Call the next bpf prog and skip the first instruction of TCC
initialization.

A total of 7 instructions are skipped:
'move t0, ra'			1 inst
'move_imm + jirl'		5 inst
'addid REG_TCC, zero, 0'	1 inst

Relevant test cases: the tailcalls test item in selftests/bpf.

Cc: stable@vger.kernel.org
Fixes: 677e612 ("LoongArch: BPF: Disable trampoline for kernel module function trace")
Signed-off-by: Chenghao Duan <duanchenghao@kylinos.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: Chenghao Duan

arch/loongarch/net/bpf_jit.c

@@ -239,7 +239,7 @@ static void __build_epilogue(struct jit_ctx *ctx, bool is_tail_call)
 		 * Call the next bpf prog and skip the first instruction
 		 * of TCC initialization.
 		 */
-		emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 6);
+		emit_insn(ctx, jirl, LOONGARCH_GPR_ZERO, LOONGARCH_GPR_T3, 7);
 	}
 }