LoongArch: No need to flush icache if text copy failed

If copy_to_kernel_nofault() failed, no need to flush icache and just
return immediately.

Cc: stable@vger.kernel.org
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: seehearfeel

arch/loongarch/kernel/inst.c

@@ -246,13 +246,15 @@ static int text_copy_cb(void *data)
 
 	if (smp_processor_id() == copy->cpu) {
 		ret = copy_to_kernel_nofault(copy->dst, copy->src, copy->len);
-		if (ret)
+		if (ret) {
 			pr_err("%s: operation failed\n", __func__);
+			return ret;
+		}
 	}
 
 	flush_icache_range((unsigned long)copy->dst, (unsigned long)copy->dst + copy->len);
 
-	return ret;
+	return 0;
 }
 
 int larch_insn_text_copy(void *dst, void *src, size_t len)